Ctrl +alt + del dont work

abhijityad said:

Press Windows+ R(Run command)
Type gpedit.msc>>>select user config>>>>Administrative templates>>>
system>>>ctrl+alt+del options enable


Your pblm may be because of virus...

The OP says that it works fine with another keyboard. It has to be a hardware problem with the keyboard.
If what you suggest is possible, then the other keyboard shouldn't have worked as well.

@DigDeep, have you tried DeaconFrost's suggestion

DeaconFrost said:

I've seen keyboards go bad when they stop handling multiple keys at once. So, give another three-key combo a shot, such as CTRL+Shift+ESC. If that works, and the keys work individually, then the keyboard is probably fine....but then the mystery deepens!