Task Manager Disabled

Method 1
Click Start, Run and type Regedit.exe
Navigate to the following branch:
HKEY_CURRENT_USER \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies\ System
In the right-pane, delete the value named DisableTaskMgr
Close Regedit.exe

Method 2
Click Start, Run and type this command exactly as given below: (better - Copy and paste) REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /t REG_DWORD /d 0 /f