"Task Manager has been disabled by your administrator"

Some people might have problem with task manager that being disable by your administrator since you are the pc administrator.

Solve -

Click Start, Run and type this command exactly as given below (just copy and paste it)

REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableTaskMgr /t REG_DWORD /d 0 /f

Run this REG fix.

Then,

• Open Registry Editor (Regedit.exe) and navigate to:

HKCU \ Software \ Microsoft \ Windows \ CurrentVersion \ Policies\ System

• In the right-pane, double-click DisableTaskMgr and set it's data to zero (0).
  

Try again press Alt-Ctrl-Del.