If you can’t open your task manager using these normal 6 methods or if you are getting an error messages like ‘Task Manager is Disabled by Your Administrator’, then you can try these methods to start your Task Manager.
Ø Open Run (Press Window key + ‘R’. More here).
Ø Then type ‘gpedit.msc’ (without quotes) in Run text box. Click OK button or press Enter key.
Ø Now ‘Local Group Policy Editor’ window will open.
Ø Now follow to: User Configuration -> Administrative Templates -> System -> Ctrl+Alt+Del Options.
Ø Now on right side, you can see some list of items. Find and double click on ‘Remove Task manager’.
Ø Now a window of ‘Remove Task Manager’ will open.
Ø Change radio button selection from ‘Not Configured’ to ‘Disabled’. Then click on ‘OK’ button.
Ø Now you can open your task manager using normal methods.
If you can’t open your Local Group Policy Editor, then open your Run command and paste this string without quotes on your Run textbox:
“REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f”
Now try to open Local Group Policy Editor to enable your disabled Task Manager.