~ Lesson 1 ~ Introduction to Windows 7 ~1 – Introduction: Networks, Protocols, LANs & WANs-A network is a group of computers that are linked together so that they can share resources.

-A shared resource could be data (folders & files), applications (MS Word), and/or hardware (printers & scanners).

-A network is usually made up of clients (computers running a client operating system) and servers (computers running a server OS).-Most clients and servers are connected together via some sort of physical cabling system.

-Each computer is installed with a Network Interface Card (NIC) that allows the computer to send data over the network to other computers.

-Networked computers can speak different "languages" or protocols. -When computers on the network "speak" the same protocol, they can connect to each other and have a "conversation". -A computer can use more than one protocol at the same time, i.e. it can be "multilingual".-Windows 7 supports the networking protocols: TCP/IP and NWLink (IPX/SPX).

-A Local Area Network (LAN) is a group of computers linked together in a relatively close physical setting, typically within the same building.-A Wide Area Network (WAN) are two or more LANs that are connected together over great physical distances.

-The Internet or World Wide Web is an example of a WAN. -Multiple corporate offices in different cities that have their computer networks connected, is another example. -WANs usually use leased phone lines (from a public phone company) to connect separate offices together.

2 – Servers and Clients-An operating system is typically marketed as either a server OS or a client OS. -A server OS allows a computer to share its resources with many clients, allows many users to access these resources at the same time (by connecting simultaneously over the network), and are usually dedicated computers used only to serve resources, users generally do not use servers as their desktop system to connect to other servers.

-Microsoft Windows Server 2008 is an example of a server operating system.-A client OS allows a computer to be a standalone system, to connect to a network and access shared resources on a server.

-Microsoft Windows 7 is an example of a client operating system.-Windows 7, although it is marketed as a client OS, can "serve" or share resources, i.e. it can act like a server, but would only be used in this capacity in a very small network.

3 – How many Windows 7 editions are there?-There are 6 main editions of Windows 7, plus 1edition that is optimized for the Intel Itanium processor; all are marketed as client operating systems.

1- Windows 7 Starter: A budget edition for casual users as well as emerging markets; it is very limited compared to other editions and does not allow the ability to join a domain2- Windows 7 Home Basic: A budget edition for home users; includes a basic set of entertainment features, but does not allow the ability to join a domain.3- Windows 7 Home Premium: Enhanced version that includes a premium set of entertainment features but does not include the ability to join a domain.

4- Windows 7 Professional: Basic edition for business users; includes basic set of management features as well as the ability to join a domain.5- Windows 7 Enterprise: Enhanced edition for business users; includes an extended set of management features and the ability to join a domain.6- Windows 7 Ultimate: Enhanced version that includes the best of the available features and the ability to join a domain, it has the same features as Enterprise, but does not come with a Volume License option.7-Windows 7 Itanium-based: Optimized for the Intel Itanium processor

-Every version except Starter and Itanium-based comes in both 32-bit (x86) and 64-bit architectures. -Starter only supports: 32-bit; Itanium-based: Itanium 64-bit.

-Comparing the editions of Windows 7: http://www.williamstanek.com/windows7-Windows 7 includes some of the revolutionary architecture improvements introduced with the Vista OS that has been further optimized.-We will be installing and administering the Windows 7 Professional edition in this NE120 course.

4 – Homegroups, Workgroups and Domains-A Windows 7 Professional system can be a member of a homegroup, workgroup or a domain.

Homegroup -A homegroup simplifies the sharing of music, pictures, documents and shared devices (printers) in a small home or office network.

-Only Windows 7 computers can participate in a homegroup; Vista, XP and older OSs cannot.-When your Network Location is set to Home, your computer will automatically start looking for other Windows 7 computers on the network (assuming you have Network Discovery turned ON).

-If you've already created a HomeGroup on your network, you'll have the option to join it, if not, you can create one.

-To create a homegroup, use the Network and Sharing Center utility. -An initial homegroup password is automatically assigned when the homegroup is created, but this can be changed at any time by any homegroup member. -If the homegroup password is changed, it must be manually changed on every computer that wishes to continue accessing resources in the homegroup.

-In order to join an existing homegroup, you must know the homegroup password. -If you have configured a shared resource on your computer and allowed it to be accessible by the homegroup, that resource is automatically advertised to and accessible from all the other homegroup systems.

-Shared folders and libraries are Read Only by default, so other members of your homegroup can read the docs, play the music, view the pictures, and so forth, but can't change them.-The two homegroup sharing permissions available are: Read Only and Read/Write.-In a homegroup, you are still able to share resources to only specific users by assigning permissions.

Workgroup (Peer-to-Peer Network)

-Workgroups are generally used in small environments that have up to 10 or 20 workstations, depending on the Windows 7 edition.

-When acting like a server, all editions except Starter and Home Basic allow 20 simultaneous remote network connections. The 21st computer trying to connect to the computer would be denied access. -Starter and Home Basic editions allow only 10 simultaneous remote connections.

-When configured in a workgroup, all Windows 7 computers are considered equals and each system is managed separately.

-Workgroup computers maintain their own local directory database (LDD) (also called Security Accounts Manager or SAM database), which is a list of the user accounts (and passwords) that can access the computer by either logging on locally or remotely over the network. -Workgroup computers do not share their directory database and security information with other computers in the workgroup. -If a user changes his password in one computer's LDD, that change would have to be made manually/separately on all other computers to which the user will connect.

-A Windows Server computer can participate in a workgroup if it is not a domain controller. This type of server is called a standalone server.

-Think of a workgroup as a "label" that makes finding a computer easy to find when browsing the network, for ex. using Network. You could have many workgroups on a single network, for ex. Accounting, Sales, Payroll, and Administration.

Domain-A domain environment is used for large numbers of computers that require centralized administration, security, and access to resources on many servers.

-A domain is a logical grouping of domain controllers and other computers that share a central Active Directory Database (ADD), containing the user account and security information for the entire domain.

-To create a domain, you must have at least one computer running Windows Server 2008 configured as a domain controller.

-On a domain controller, user accounts are not stored in a local directory database but in a centralized Active Directory Database (ADD), that is stored on every domain controller in the domain.

-This ADD database is automatically replicated (copied/updated) to all domain controllers in the domain when a change is made in one of the copies. -Users that log into the domain can have access to all servers in that domain using a single logon user account, unlike a workgroup where user accounts are decentralized and managed separately on each computer.-If a domain user changes his password, the change will automatically (without intervention) be updated on all domain controllers in the domain; making administration for a large domain simple and straight-forward.

-A Windows Server computer can play one of 2 roles in a domain: a domain controller that has a copy of the domain’s ADD, or a member server which does not have a copy of the domain’s ADD.

-Since every domain controller stores a copy of the domains ADD, it can authenticate incoming domain logon requests. -Member servers do not store a copy of the domains ADD, but have their own LDD like computers in a workgroup.

-Member servers cannot authenticate domain logon requests. -Member servers are generally used for dedicated application servers, for example, a web server.

-For clarification, a member server is a non-domain controller that is a member of a domain, a standalone server is a non-domain controller that is a member of a workgroup.

-Only Windows 7 Professional, Enterprise and Ultimate editions can become a member of a domain, and once a member, can log into the domain and access its shared resources as a client.

-In order to join a domain the following is required:-Domain Name: The DNS-compatible domain name of the domain you with to join, for ex. neit.edu-Computer Account: A domain administrator must have created an account for your computer in the domain, or if this has not been done, if you have a domain administrator username and password, you can create the account during the installation-Available domain controller and server running the DNS Service: At least one domain controller in the domain must be online when you attempt to join the domain-You can join a domain during or after the Windows 7 installation.

5 – Logging In-Windows 7 offers two options for logging on locally: the Welcome Screen and the Classic Logon screen.

Welcome Screen Classic Logon

-In a homegroup or workgroup, the default is the Welcome screen, which lists all standard and administrator accounts that have been created in the LDD. To log on, click the username's icon name and enter the user's password (if one has been assigned).-To force the use of the Classic Logon screen you must edit the local security policy and Enable the Interactive logon: Do not display last user name setting, which will disable the Welcome screen.

-Windows 7 has a Fast User Switching feature that can be used when one user is logged into a computer, another user can log on without requiring the current user to log off. (Start > > Switch user) -Generally, there are two different types of logons:

-Locally: You are sitting at the computer's keyboard and the computer has a local directory database-Remotely (over the network): You are not sitting at the computer you are trying to access; you are sitting at a computer that is connecting to another computer that is sharing resources (acting like a server)

-To log on to a computer running Windows 7, you must provide a user name and password. -User name: A unique logon name assigned to you by an Administrator; they are not case-sensitive-Password: The password assigned to your user name; passwords are case-sensitive and appear as an * to protect it from onlookers. -User name and passwords should be kept secret.

-When a user provides a user name and password combination (when logging in locally or remotely), Windows 7 compares it to its user account list, its LDD, and if the information matches what's in the database, the user is authenticated and allowed access, if not, access is denied.

-When a computer is in a workgroup and the user is logging in locally, the user is authenticated by the LDD on that computer.-When a computer is in a workgroup and the user is logging in remotely (to another computer in the workgroup), the user is authenticated by the LDD on the computer that is sharing the resource. -If the computer is part of a domain, and the user is logging into the domain, the user is authenticated by the ADD on a domain controller. -When a user is authenticated, an access token is created that identifies the user and the groups the user is a member of.

6 - Windows Security Options-By pressing (together), these Windows Security options appear:

Security Options Task Manager

-Lock this computer: Secure the computer without logging off; similar to a password protected screen saver; if a user forgets his password, an administrator can unlock the computer for him-Switch User: When you want more than one user to log in locally without logging off the current user -Log off: Logs off the current user and closes all running programs but leaves Windows 7 running

-Change a password: Allows you to change your or another user's password; you must know the old password in order to change to a new one using this method-Start Task Manager: Provides a list of running programs, processes, performance, memory use, etc.

-When using the Start button to Shut down, Switch user, Log off, Lock or Restart the computer, click the arrow to the right of Shut down, to select another option.

7 – Hardware Requirements -You must make sure that the computer you want to install Windows 7 on, meets (or exceeds) the minimum hardware requirements for physical memory, processor, hard disk space and graphics capabilities.-Hardware Requirements for Windows 7 Professional:

MinimumCPU 1 GHz for both 32-bit (x86) & 64-bit (x64)Memory 1 GB (x86); 2 GB (x64)Hard Disk Space 16 GB free (x86); 20 GB free (x64)Graphics DirectX 9 (WDDM 1.0 or higher)

-If you have only the minimum hardware requirements for Microsoft Windows 7 Professional your system will be extremely slow, but you will be able to install it. *Minimum requirements are NOT recommended for a workable system!.-If you want a machine with more than the minimum requirements, maximize memory (RAM) and install a high-powered processor. These two will have the greatest effect on your computer's performance.

Windows Catalog-You can install many types of hardware to your Windows 7 system (cd/dvd writers, NIC cards, printers, scanners), as well as many different types of software (Microsoft Word, Adobe Photoshop). -Before you purchase or attempt to install any software and hardware in your system, make sure to check the Windows Catalog in the Windows 7 Compatibility Center on the microsoft.com website.

-Notice you can check compatibility for both software and hardware, for both 32-bit and 64-bit versions of Windows 7, and specify whether it is simply compatible or whether it has passed full Windows 7 Logo certification. -If for some reason a product does not appear in the catalog, it does not necessarily mean that it will not work with the operating system; contact the manufacturer to make sure that compatibility is in the process of being achieved.-Before upgrading to Windows 7, it is suggested to download the Windows 7 Upgrade Advisor to check your existing hardware and software for requirement and compatibility issues. (www.microsoft.com/downloads)

8 – Windows 7 Pre-Installation-Before installing you will need to decide whether you will be installing the 32-bit or 64-bit version of the Windows 7 operating system.

-The 64-bit version can only be installed on a computer that has a 64-bit processor. -It can recognize from 1 to 192 GB of RAM memory. -It only supports 64-bit hardware drivers, so make sure all installed hardware has a 64-bit driver that is compatible (preferably with the Windows 7 Logo).-Most 32-bit applications will run on a 64-bit OS.

-The 32-bit version can be installed on computer that has either a 32-bit or 64-bit processor.-It will only recognize up to 4 GB of RAM memory.

-Each version, 32-bit or 64-bit, has its own separate distribution media, in other words one DVD will not hold both versions, there will be a separate installation media for each.

-Next, you should decide whether you want to do an upgrade or an install.-You can only upgrade from Vista Home Basic, Home Premium, Business, and Ultimate editions to the same Windows 7 edition, with the exception of Vista Business which is upgraded to Windows 7 Professional.

-An upgrade will attempt to retain all the applications, users and settings configured in Vista while simply upgrading the OS files to Windows 7.-If you are running any other Windows OS (other than the Vista editions listed above), you must do an install and not an upgrade.-To start an upgrade, boot into the current Vista operating system, log in as a user that has Administrative rights, and start the Windows 7 installation wizard.

-If you choose to do a clean install, Windows 7 will be installed with the default OS settings that are configured by the Installation Wizard.

9 – Installation Methods-There are many different methods for installing Windows 7, you could:

-Boot to the Windows 7 DVD, which will automatically start the Installation wizard-Do not boot to the Windows 7 DVD, but boot to an existing installed OS, then go to the DVD and run the SETUP.EXE file, which will start the Installation wizard.-Copy the installation files to a shared folder on a network server (a distribution server), and do the installation over the network-Do an unattended installation using an answer file that provides the installation responses that are entered interactively in an attended installation-Use the Microsoft Deployment Toolkit (MDT) 2010 to automatically distribute Windows 7 images over the network with "Zero Touch" interactivity-Use Windows Deployment Services (WDS) to deploy Windows 7 images over the network (typically used in conjunction with the MDT).-Use Sysprep.exe to prepare a computer for disk imaging, which can then be captured using ImageX (a new imagine management tool included with Windows 7).-Using the Windows Automated Installation Kit (AIK) which is a set of utilities and documentation that allows an administrator to configure and deploy Windows OSs.

-Make the choice based on what type of installation works best for your environment. -Do you have only a few computers to install or many? -Are all the computers clones of each other or do they have different configurations? -Do you want to take the time to setup the infrastructure needed for automated installations using one of the deployment tools?

10 – Windows 7 Install -To start a manual installation, go to the Windows 7 installation media (either a DVD, download .ISO file, or a distribution server) and run the SETUP.EXE program.

-If you booted to the DVD and have autorun turned on, this program starts automatically. -The SETUP.EXE program starts the Windows 7 Installation wizard that walks you through the installation process, prompting when necessary for information about your configuration.-The setup program uses an Install.wim image file that is stored in the \Sources folder of the install media.-The installation is split into 3 main phases: Pre-installation, Online Configuration, and Windows Welcome.

-The steps to install Windows 7 are as follows:1- Run SETUP.EXE to start the Windows 7 Installation wizard2- Specify your language, regional and keyboard settings

3- Choose to Install now, learn What to know before installing Windows or Repair your computer. To install click the arrow.

4- Read and accept the licensing terms

5- Choose to either do an Upgrade or a clean Install

-Note, when doing an Install to the same volume as the existing Windows operating system (like XP or Vista), the setup program will make a copy of the existing user profiles, program files, and the Windows folder in a directory named Windows.old before installing Windows 7; the old OS will no longer be available.

6- Select a volume (that is at least 16 GB for a 32-bit installation) on which to install Windows 7. It can be either an existing volume, or you can create a new one by selecting Drive options (advanced). -A simple volume/partition is a logical division of a physical hard drive. -Windows 7 by default will be installed into the \Windows folder on the selected volume.

7- Installing Windows: Copying Window files, Expanding Windows files, Installing features, Installing updates, and Completing the Installation-You will be given a progress meter to show how far each process has completed.-After this portion of the installation completes, your system will automatically reboot.

8- Enter a User Name for your Initial User account and the Computer Name for this computer-The Initial User account created is automatically given administrator privileges and has no password. -The Computer Name can be up to 15 characters long and must be unique on the network (cannot be the same name as any other computer, domain or workgroup).

9- Set your Password (twice) and your Password Hint (that will help you remember your Password if you should forget it).-Note, passwords are case-sensitive, a blank password is allowed by default, and if you forget the password you enter here, you may have to reinstall Windows 7.

10- Enter the 25-digit Product Key for this legal copy of Windows 7.

11- Configure Windows Updates options

12- Set your Time zone, Automatic daylight savings time adjustment, Date and Time

13- Set you computer's current location; this will be your Network Location and will affect the automatic membership in a homegroup, workgroup or domain. -If you select Home network you will be able to create the homegroup, if you select Work network you will be able to join either a workgroup or domain.

14- If you selected Home network, you will be asked to specify the files and printers that will be accessible by the other computers running Windows 7 in the homegroup, and to set the homegroup password.-If you selected Work network, you will automatically become a member of a workgroup called WORKGROUP.

15- Setup will now finalize the installation and start Windows 7 logged in as the initial user account.-After the installation is complete, make sure to install the latest Service Packs and system updates since they are critical for maintaining the highest level of security and system performance.-The setup program automatically creates a Windows Recovery Environment (Windows RE) and installs additional components that can be used for recovery and troubleshooting.

-These recovery tools are always available and include: Startup Repair, System Restore, System Image Recovery, and Windows Memory Diagnostics.

11 – Post-Installation -During the Windows 7 installation, the setup program attempts to automatically detect and install the networking hardware.

-If a NIC card is detected, the appropriate driver is installed, and if a DHCP server is available, it is contacted for an automatic IP Address assignment.

-If a NIC is not detected, you may be able to install it manually assuming a compatible driver is available.

-By default, a typical network installation installs the following services/components:-Client for Microsoft Networks (Workstation service): Allows this computer to gain access to shared resources on other Microsoft computers. (Allows this computer able to be a "client”)-QoS Packet Scheduler: Provides network traffic control including rate-of-flow and prioritization; it gives priority to traffic requiring constant bandwidth, for ex. voice over IP-File and Printer Sharing for Microsoft Networks (Server service): Allows other computers to gain access to shared resources on this computer. (Allows this computer able to act like a “server”)-Internet Protocol Version 4 and 6 (TCP/IPv4 & TCP/IPv6): The default networking protocol that allows your computer to communicate over a LAN and WAN.-Link-Layer Topology Discovery Mapper I/O Driver and Responder: The I/O Driver is used to discover and locate other PCs, devices and network infrastructure components on the network. The Responder allows this computer to be discovered and located on the network.

12 – Action Center and Windows Activation-Windows 7 has a new Action Center that monitors and reports the status of important security and maintenance areas.

-You can access the Action Center by clicking the icon in the lower right-hand corner of the Taskbar.-Note, if there is a red circle with an X on the flag, that means there is an issue and message for you.-You can also access the Action Center by going to: Control Panel > System and Security > Action Center.-If a problem has a solution, you can click the View Problem Response button.

-If you click Change Action Center settings you can customize the messages you will receive.

-All retail versions of Windows 7 require a valid Product Key must be activated after installation. -You can determine if your Windows 7 installation has been activated by going to: Control Panel > System.

-Automatic activation will be attempted 3 days after installation, you must activate within 29 days to be able to create new files and save changes, and to continue using all OS features.-You can start the activation manually by clicking: Activate Windows now.

~ Lesson 1 ~ Review Questions ~1. Describe a network.

How do computers physically connect to each other?

2. Describe a protocol.

Can a computer have more than one protocol installed at one time?

3. What is the difference between a LAN and a WAN?

4. What is the generic definition of the word "server"?

…"client"?

5. Windows 7 is marketed as a _____________________ operating system.

Give an example of a server operating system.

Can a Windows 7 computer act like a "server"? Explain.

6. List the 7 Windows 7 editions.

Which edition only comes in a 32-bit version?

Which 3 editions cannot become a member of a domain?

7. Describe a homegroup.

Only computers installed with the ________________________________ operating system can participate in a homegroup.

In order to create or join a homegroup, your Network Location must be set to __________________________.

In order to join a homegroup, you must know the homegroup ________________________________.

8. The default permission assigned to a homegroup shared library is ___________________________________;

it can also be set to _________________________________________.

9. Describe a workgroup (peer-to-peer network).

Can a Windows 7 computer join any workgroup?

10. All Windows 7 editions except Starter and Home Basic allow ___________ simultaneous network connections.

Starter and Home Basic allow only _________ simultaneous network connections.

11. Can a Windows Server (2003/2008) computer participate in a workgroup? What must NOT be true about this server?

What is this type of server called?

12. Each computer in a workgroup maintains a _____________________ directory database, which is a list of user accounts and resource security information for that computer only.

This is also called a __________________________________________________ or ___________ database.

13. Administration in a workgroup ( centralized / decentralized ).

14. If a user wanted to change his/her password in a workgroup, what would need to be done?

15. Describe a domain.

What type of server is needed to create a domain?

16. Describe a domain controller.

What type of operating system must a domain controller be running?

What type of directory database do domain controllers have?

17. Briefly describe the Active Directory Database (ADD) that is used in a domain.

18. Can I create a domain if all my computers are running Windows 7? Why/why not?

19. Administration in a domain is ( centralized / decentralized ).

20. Do domain controllers share their Active Directory Database with other computers in the domain? Which ones?

Do domain controllers validate domain user authentication/logon requests?

21. Describe a member server.

22. What is a member server usually used for?

Does it validate domain logon requests?

What type of directory database does it have?

23. Can a Windows 7 Professional computer be a member of a domain?

24. What is necessary for a computer to join a domain?

25. Windows 7 offers what 2 options (screens) for logging on locally?

26. Describe the Welcome Screen.

27. Describe the Classic Logon screen.

28. Describe Fast User Switching

29. Describe Logging on Locally.

…Logging on remotely.

30. What pieces of information must be provided to be authenticated by a Windows 7 system (2)?

What does an access token do?

31. Are user names case sensitive?

32. Are passwords case sensitive?

33. What key combination is used to display the Windows Security options?

34. Describe each of the following (Make sure to include whether the current user is still logged on, open applications are still running, and if the Windows 7 OS is running):-Lock this computer:

-Switch User:

-Log off:

-Shutdown:

35. If a user locks his workstation but forgets his password, who can unlock the workstation?

36. Is it suggested to install Windows 7 on a computer that has the minimum hardware requirements? Why/Why not?

37. Describe the Windows Catalog and why its important.

Where can you find the most up-to-date version of the Windows catalog?

If a device is not listed in the catalog, does that mean that it cannot be installed?

Will Microsoft support devices not listed in the catalog?

38. What program can be downloaded and executed to check for existing hardware and software requirements and compatibility?

39. Describe the differences between a 32-bit and a 64-bit OS. (Make sure to include processor requirements and maximum recognized RAM limits.)

Does a 64-bit Windows OS require 64-bit drivers?

40. List the 4 Vista editions that have direct upgrade paths to their Windows 7 counterparts.

Can you upgrade directly from XP?

41. What is the difference between an upgrade and an install?

42. Describe a distribution server.

43. Is the Windows 7 DVD bootable?

44. To start a manual installation, execute the _______________________________________ program.

45. When doing an Install to the same volume/partition of an existing Windows OS, the setup program will make a copy of the existing user profiles, program files, and the Windows folder in a directory named

___________________________ before installing Windows 7; the old OS will no longer be available.

46. Describe a volume/partition.

By default, Windows 7 will be installed to what folder on the selected volume?

47. The Initial User name entered during the installation is automatically given _____________________________ privileges.

48. Describe a computer name. What are some requirements?

49. If you forget the password assigned during setup, what can help you remember?

50. Can a Windows 7 Professional computer automatically adjust your clock for daylight savings changes?

51. List the 3 different Computer/Network Location options.

If Home network is selected, you can become a member of a ____________________________________.

If Work network is selected, you can become a member of either a

____________________________________or a ___________________________________.

By default, if Work network is selected, you become a member of a __________________________________

named ____________________________________.

52. Describe the following Windows 7 networking components (include the service name if given):-Client for Microsoft Networks:

-QoS Packet Scheduler:

-File and Printer Sharing for Microsoft Networks:

Link-Layer Topology Mapper I/O Driver and Responder:

53. What is the default networking protocol for Windows 7?

What are the 2 different versions of this protocol?

Can it be used to connect to computers both on a LAN and WAN?

54. Describe the Action Center.

How can you access the Action Center?

55. Describe Windows 7 activation.

~ Lesson 1 ~ Critical Thinking ~

You have been hired as a consultant for the 4 different types of companies described below.For each example, would you suggest a homegroup, workgroup or a domain?

*Specify any special configuration if it is required.*Specify the Windows 7 edition(s) that could be used for each.

1. A home network with 4 computers. The users do not know how to configure user accounts, shared folders and permissions.

2. A company with 300 employees that is growing. They will have an IT department in place.

3. A realtor's office with 15 employees.

4. A small company with 22 employees. They do not want to learn how to administer Active Directory, but have resources that all 22 employees should be able to access simultaneously.*Hint: The 10/20 simultaneous users is a limit of what OS?

~ Lesson 1 ~ Introduction to Windows 7 ~~ Lesson 1 ~ Review Questions ~~ Lesson 1 ~ Critical Thinking ~