I have a desktop PC which was recently moved. Since moving I've noticed that even while the PC is turned off (but wall socket turned on) the NumLock LED on the keyboard is on.
It may have been doing this before the move, but I've only noticed it now.
Maybe it matters that the keyboard is connected via a shared mouse/keyboard PS/2 port and I'm running Windows 7.
I've not checked whether the LEDs are just keeping whatever state they were in when I turned the PC off but will do this if that information could be relevant.
Why does the led stay on when the PC is turned off and how can I prevent this?