CPU Usage VERY High

I'm hoping I can resolve an issue here. First let me start out by apologizing for this long post, but i'm trying to get as much info out as I can.Recently i've been having big problems with my computer running VERY slow, my computer takes 5 minutes to boot up when normally it would only take 1, my mouse moves very laggy, and I can't start up any programs without having to wait minutes just for it to start. When I look at the performance monitor, my CPU usage is anywhere from 50%-100%...and i'm not even running anything! First let me get somet things out of the way. First off I have a laptop with AMD Athalog 64 2.5 ghz processor, 1.0gig of ram, and a ATI X600 mobility video card. I've had my computer for a little over a month so it's not outdated or anything, and all of my drivers are up to date.

I did a viruscan on my computer which took very long b/c my CPU usage was very high, and nothing negative came back when I did so. I ran adaware and removed all of the adware I had.still didn't fix the problem.
After trying both of those things I decided i'd try to restore my computer to an earlier point. it was successful. That was a couple days ago when I was having this same problem. Well here we are present date, and i'm having the same problem again. I tried restoring my computer to an earlier point again, but this time it resulted with some troublesome problems, apparently an important ATI file was deleted or something (not sure exactly) and I couldn't boot my computer up in normal mode, I had to go back into safe mode and rollback the drivers for my computer to even boot up. That was approximately 30 minutes ago, and here i am now. Obviously restoring didn't help this time because my computer is very slow at the moment.

I don't get it, because both times this has happened, it comes out of no where. My computer will be running just fine, then 'BAM!' out of no where my CPU usage is out of the roof. I'll try restarting, closing everything on my toolbar nothing works. Speaking of toolbars, mine is pretty empty, it's not overloaded with a bunch of crap, mostly just important stuff like firewall and virus scan. I can't imagine that restoring my computer is the only option here. There has to be something that is causing this, that i'm not detecting. Originally I would have guaranteed it was a virus, but McAfee Virusscan isn't picking up anything. And it's obviously some software issue, because when I tried restoring my computer a few days ago when I was having this problem, everything ended up working normally after that. This time when I tried it though, there was no luck.