When multiple users are logged on to Windows XP, using Fast User Switching, your computer runs slowly?
If logged on users have programs running, this is expected behavior.
To resolve the issue, use any of the following:
1. Shutdown and restart the computer, which terminates the other users processes.
2. Log of a user:
-Log on with administrator privileges.
-Press CTRL+ALT+DELETE and start Task Manager.
-Select a user and press Logoff.
NOTE: Do not End Task as this can have unexpected results.