NOTICE: Always be careful when editing the registry. Sometimes changes to the registry affects Windows in undocumented ways. You should always make a backup of the registry before making changes. You can make a backup using your registry editor.

Windows includes a nifty feature that allows you to disable the task manager such that it can not be used to circumvent certain local security measures. However, many spyware programs utilize this feature to an unscrupulous end - spyware uses the feature to keep you from stopping spyware. A common message that occurs is “Your administrator has disabled the Task Manager” dialogue upon Ctrl + Alt + Del. To fix this problem, go to Start -> Run -> regedt32 and navigate to HKEY_Current_User\Software\Microsoft\Windows\CurrentVersion\Policies\System.
Set the value “DisableTaskMgr” to “1″ if you wish to disable the task manager or “0″ if you would like to set it to being enabled.