Cant log off / switch users on Windows XPpro

So I'm sitting here at this very moment and I cant switch users or log off, I let my nephew use it to play a game on an account I made just for him, but now I need to use the computer and every time I go to log off of his account NOTHING happens when I press the yellow log off button the little screen goes away but nothing else happens after that, its the same for switch users too.
I dont know if shutdown will work either but can anyone explain why this weird thing happened.

8 year olds cant cause this much damage to a computer can they?

Yes. Yes, they can.

>>2
Only with an administrator account, I sure hope >>1 doesn't let strangers (anyone but yourself) use a computer without limiting their user accounts.

You probably disabled the necessary services that allow for fast-switch or multiuser.

>>3
I had to push the power button in to turn it off. and his account is restricted its not an admin, I just cant figur out what he did
I have never heard of this before. next time I think I'll supervise
him more.

>>4
I have no idea how or where to go to disable fast-switch and multiuser I think its Controlpanel>>user accounts, or something like that.

and now Im not sure if I had him on a restricted account or not oh well this can be fixed.

this happened to me you need to replace a file that was damaged in the registry i dont know it off hand, google it but that is the solution

>>7
thanks I look it up

Have you tried System Restore yet?

>>9
yes thats What I did and it seems to have fixed it.