I hope i am in the correct forum( )

Now i have a problem:

1)I cant shut down my PC after long downloads (around 3hrs) I can shut it down before that properly so do you have any idea what might be causing this?? if so plz help.

You can't shut it down, how ? And unplug it or just hold the Power Button.

Can you clarify how you "can't shut it down"? Does it give you some error, or just hangs up, or what?

No no everything works perfectly and smoothly only when i press the "Shut Down" button in windows 7 Nothing happens literally NOTHING. again when i press Ctrl + Alt + Del again NOTHING HAPPENS. not even the security options come up. I cant start Task manager so i cant shut down windows normally(by pressing shut down or Alt + F4) i have to unplug it any solution??