How To Enable Task Manager
Click OK The Registry Editor will now open
Browse to the following key:
In the right pane, look for the value: DisableTaskMgr
Right click DisableTaskMgr and select Delete. (When prompted with "Are you sure you want to delete this value", select Yes.
Close the Registry by choosing
You should now be able to access Task Manager. If not, reboot into Safe Mode and repeat the steps outlined above.
If you have Windows XP Professional and access to an administrative user account, you could change the registry editor options in the Group Policy Editor.
1. Click Start, Run
2. Type GPEDIT.MSC and Press Enter
3. Go to-->* User Configuration-->* Administrative Templates-->* System
4. In the Settings Window, find the option for "Prevent Access to Registry Editing Tools" and double-click on it to change.
5. Select Disabled or Not Configured and choose OK
6. Close the Group Policy Editor and restart your computer
7. Try opening REGEDIT again