Freezing problem, please help.

For the last week, my comps been freezing completely to the point where i have to restart it because it never unfreezes. Sometimes it won't even leg me log in, other times i log in and then i see my display screen and then it freezes. Sometimes it works for a few minutes, like now. It's different every time. All programs are frozen, i can't even open my Task Manager but my mouse is still able to move.

I've had my comp for about 2 years now and never dealt with any form of freezing before now.

The only thing different i've seen is for the last few weeks when i start up my comp, a folder will open as soon as i log in called "Common" and has file in it like "helper.dll", i always exited out of it cause i didn't know what it was.

Other than that, when i open my task manager, it shows all my start up programs opening abnormally fast now. I have MSN that opens on start up, but it's always taken a minute or so, the start up going slow. Now, when i click on TM, it shows it's already almost open, as well as all the other programs i have on start up.

Is it a virus maybe? Something that's making all my programs randomly open and that's what's causing my comp to freeze? Anyone have any idea?

Thanks.

btw, i wasn't sure where to post this so sorry if it's the wrong place.