To prevent users from killing important processes like antivirus scanning or usage monitoring, use the Group Policy Editor to disable the Task Manager. Log on as an administrator, launch Gpedit.msc using the Start menu’s Run dialog. Navigate to UserCon figuration\Administrative Templates\System\Ctrl+Alt+ Del Options. In the right-hand pane, double-click on Remove Task Manager and change its status to Enabled. You can still launch the Task Manager by right-clicking onC:\Windows\System32\TaskMgr.exe, choosing Run As…, and using the Administrator password.

This works in Windows XP Pro and 2000 only; Windows XP Home lacks the Group Policy Editor. To accomplish something similar in Win XP Home, log on to each user account and edit the Registry. In HKEY_CURRENT_USER\ Software\Microsoft\Windows\CurrentVersion\Policies\ System, create a DWORD value named DisableTaskMgr, and set its data to 1. Do the same in the key HKEY_ USERS\Default\Software \Microsoft\Windows\CurrentVersion\Policies\System.

Courtesy of PC Magazine