How to enable Task Manager again in Windown XP?

Task Manager has been disabled by the Administrator'. The funny thing is that I am the Administrator, and don't know how this happened. The strange thing is that it is only on the Administrator user identity that I get this problem, but am able to operate Task Manager from other user identities. Any ideas? "

for this type of problems follow this steps

* Click Start -> Run. Type in "regedit" (no quotes) and hit Enter.

* Search for HKEY_CURRENT_USER -> Software \ Microsoft \ Windows \ CurrentVersion \ Policies \ System.

* Look for: DisableTaskMgr. Click on REG_DWORD. Value: 1=Enable this key (disables TaskManager); Value: 0=Disable (actually enables TaskManager)

* Close RegEdit

* Reboot your machine.