Taskmanager has been disabled by administrator

Taskmanager has been disabled by  administrator
this error occurs when computer gets infected with virus, trojan, or piece of spyware
To open the Task Manager, you might normally do one of the following:
1)Press CTRL+ALT+1DEL on the keyboard
2)Press CTRL+SHIFT+ESC on the keyboard
3)Right-click on the taskbar and choose Task Manager
then you may find this error message

there are couple of ways to fix this problem:
METHOD 1:
Using the Group Policy Editor
Click Start -->run-->type gpedit.msc and ok
next select user configuration--> administrative templates -->system-->ctrl + alt + del options -->select remove task manager option -->double click on it
Choose the option "Not Configured" and click Ok.


METHOD 2:
start-->run and type (paste code)
REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /t REG_DWORD /d 0 /f


METHOD 3:
start-->run -->regedit and ok
next select HKEY_CURRENT_USER-->Software-->Microsoft-->Windows-->currentVersion-->Policies-->System


find and delete the value named DisableTaskMg ,set the value to 0
hope your problem gets rectified:)