Problems with programs shutting down

Hey Guys,

Sorry this is on notebook review i didn't get much help on desktop review and im about to kill my computer

Problems with most programs closing
Well My computer is a custom BUild.

AMD X2 core processor
2.2 ghz
2 GB Ram
Geforce 8600 GT Graphics card 256 i think?

Works good for the well for the most part, a problem im coming across with tonight is, all programs are closing from pressing a simple button on the key board. Except for google chrome which i use for internet. This has neverh appened before. I was using Cyberlink earlier and it started closing when i would hit any key and i thought it was just that program so i uninstalled restarted, the whole works.. Didn't help and now all programs close when you hit a simple "." key. Im not sure why this is happening? Any help would be appreciated. I had a file that downloaded today that had a virus in it, trojan . dropper, hackkit, and info stealer, norton blocked it all and removed it along with a bloodhound, so i don't know if thats still causing it. Ive now done a system restart, and ran a couple other virus scanners.

What's happening is say i open, programs like chrome, notepad control panel, nothing happens with an key. however, yahoomessenger, cyberlink powerdirector mozilla, all even when its starting up i can hit a number or d or other buttons and it cancels the start up or if the programs are already open it just shuts them!

Please help

Its odd i can click virtually any key and programs close?

help

 

I need to get it working again, i don't know why its doing this, any help would be appreciated.