Chapter 6: Sharing Your Computer with Multiple Users

Using a Shared Computer

Unlike Windows Me/9x, with Windows XP you are always logged on with a user account (either a local user account or a domain account). If you haven't yet set up user accounts, you are logged on automatically as Administrator or Owner. Once you set up additional user accounts, you can log on as any user (as long as you know the appropriate password), logging out when you are done. Using the new Fast User Switching feature, you can also switch from one user account to another in the middle of your work.

Don't use Administrator, Owner, or any administrator account for your day-to-day computer work. You can do less accidental damage from a limited account.

Logging On

Once you have created user accounts, whenever your computer powers up or a user logs off, you see a logon screen. If you are not on a LAN, or you are connected to a peer-to-peer workgroup-based LAN, you normally see the Welcome screen, as shown in Figure 6-10. If your system is configured to display the Classic logon screen, or your computer is connected to a domain-based network, you see the Log On To Windows dialog box instead. Either way, click or type your user name and type your password, if your account has a password (and we recommend that it does). Windows loads your user account and you see your desktop.

Figure 6-10: The Welcome screen greets you when you start up Windows, log out, or press Windows-L to switch users.

When you see the Welcome screen, you can switch to the Classic logon screen by pressing CTRL-ALT-DELETE twice. This trick is useful if you want to log on using the Administrator or Owner account that Windows creates automatically but doesn't usually display on the Welcome screen.

Resuming Work after Locking Windows

If your computer is configured to use the Welcome screen for logging on, pressing WINDOWS-L (that is, holding down the WINDOWS key and pressing L) to lock the computer also displays the Welcome screen (see Figure 6-10). Log back in to continue working. If your computer uses the Classic logon screen and you press WINDOWS-L, you see the Unlock Computer window, prompting you to enter your password to continue. Since Fast User Switching isn't available with the Classic logon screen, if you log on as another user, Windows logs off your original user account.

Logging Off

If you are done working, but you don't want to shut down the computer, you can log off. Choose Start | Log Off, and click the Log Off button to confirm that you mean it. Windows exits all your programs, logs you off, and displays the Welcome screen (or the Classic logon screen).

Switching Users

When Windows starts up, you choose which user to log on as by clicking or typing the user name in the Welcome screen or the Classic logon screen. If Windows is already running, you can switch users by logging off and letting the other user log on.

Fast User Switching provides a faster way to switch users: pressing WINDOWS-L. Alternatively, you can choose Start | Log Off, and click the Switch User button. When you see the Welcome screen, log on as another user. When you switch users with this method, Windows doesn't exit the programs you were running: instead, they continue running in the background until you switch back to the first user account.

Setting the Screen Saver to Require You to Log Back On

If you are worried about someone using your computer when you step away from it, you can set the screen saver to require you to log back in using your user account name and password. Follow these steps:

1. Right-click a blank place on the desktop and choose Properties to display the Display Properties dialog box.
2. Click the Screen Saver tab and set the Screen Saver box to an option other than None.
3. Select the On Resume Display Welcome Screen check box.
4. Click OK.

Now when you return to your computer and click a key or move the mouse to wake Windows up, it displays the Welcome screen.

Changing Your Password

You can change your own password any time. Follow these steps:

1. Choose Start | Control Panel, and click User Accounts to display the User Accounts window (see Figure 6-1).
2. If you have an administrator account, you see the list of user accounts. Click yours.
3. Click Change My Password. (If you are an administrator changing someone else's password, the command is Change The Password.)
4. Type the existing password and your new password (twice). Also type a password hint, to remind you of your password if you forget it.

If you created a password reset disk for your user account, you don't have to create or modify the disk when you change your password.

Be sure to create a password reset disk for yourself: it saves lots of headaches if (when) you forget your password. Choose Start | Control Panel, click User Accounts, and choose Prevent A Forgotten Password from the Task pane.

Keeping Your Files Private

If Simple File Sharing is disabled on your computer (as described in the section "What Is Simple File Sharing?" earlier in this chapter), your folders are stored on a drive or partition formatted with NTFS, and you use Windows XP Professional, you can see and set who has permission to open your folders or files.

To see the permissions for a file or folder, right-click it in an Explorer window and choose Properties from the shortcut menu that appears. You see the Properties dialog box for the file or folder. Click the Security tab, which only appears for files and folders on NTFS drives when Simple File Sharing is disabled (see Figure 6-11).

Figure 6-11: The Security tab of the Properties dialog box for a file

The Security tab shows who has permission to do what with the file or folder. Table 6-5 (which appears earlier in this chapter) lists what these permissions allow. Select an entry in the Group Or User Names, and the permissions for that group or user account appear in the Permissions list in the lower part of the dialog box. For permissions that are allowed, you can click the Deny check box to revoke this permission for this user or group. For permissions that are denied, you can click the Allow check box. If you don't have permission to change the permission, the check box appears dimmed.

Sharing Files with Other Users

To store your files so that other users of your computer can read, edit, or delete them, store the documents in the Shared Documents folder that appears under My Computer in the folder tree. (This folder is actually called C:\Documents And Settings\All Users\Shared Documents, assuming that Windows is installed on C:.) All users, including the Guest account, can open the files in the Shared Documents folder. To see the Shared Documents folder, choose Start | My Computer and click Shared Documents in the Other Places part of the Task pane.

If you haven't disabled the Guest account, then files in the Shared Documents folder can be opened by anyone who uses the computer.

If you want only some people to be able to read or modify material you store in Shared Documents, see the preceding section for how to set the permissions for a file or folder.

Running a Program as Another User

If you know the password for another user account, you can run a program as if you were logged on as that user. Some older programs can't run unless the user account has full rights on the system (for example, it insists on making system configuration changes that would ordinarily be forbidden for your user account). The Run As dialog box enables you to run a program and specify what user account to run it as.

To see the Run As dialog box (shown in Figure 6-12), hold down the shift key while you right-click an icon for the program (either on the desktop or in an Explorer window). Choose Run As from the menu that appears. In the Run As dialog box, click The Following User, type the user account name, enter the password (or leave the Password box blank if the user account has no password), and click OK.

Figure 6-12: You can run a program as if you were logged on as another user.

Instead of typing the user account name, you can try clicking the down-arrow button at the right end of the User Name box to see a list of user accounts. If no accounts appear, type the computer name, a backslash, and the user account name to specify a user on your computer. For example, if your computer's name is GRACELAND and the user account's name is Elvis, type GRACELAND\Elvis.

You can create a shortcut to a program that is set to run a program as another user. Follow these steps:

1. If the shortcut doesn't already exist, create it: Right-click the program's icon on the desktop or in an Explorer window and choose Create Shortcut from the menu that appears (or use another method to make the shortcut).
2. Right-click the shortcut and choose Properties to see the Properties dialog box for the shortcut.
3. Click the Advanced button on the General tab. You see the Advanced Properties dialog box, which offers the Run With Different Credentials option, as shown here:

4. Click the Run With Different Credentials check box and click OK.

Each time you run the shortcut, Windows displays the Run As dialog box (shown in Figure 6-12) to ask you for the user name and password. Or, you can right-click the shortcut and choose Run As to see the Run As dialog box (no need to hold down the SHIFT key).