network cable unplugged?

Well, I've already submitted a thread about this before, got it fixed or I thought I did. For some reason my computer runs at 100% CPU usage a lot & from what I heard it shouldn't run like that, that is one problem. When it does sometimes after a period of time it kicks me from the internet and says a Network cable is unplugged, and that is the other. I don't know why. Last time, someone told me that my computer may run at 100% CPU constantly because I have spyware or a virus. So I scanned, and indeed I had a few spyware and virus problems. Got that fixed, and didn't have this problem for about 2 weeks. The computer didn't run at 100% over a long period of time, and my internet stayed connected. Now it is back again. This time there is no spyware or virus problems. Also sometimes I could just be browsing the web and it goes to 100% CPU usage, and not just short burst of it, it stays until I close out the web browser. I'm lost on what to do. Does anyone else have this problem, or know why it is does it, and if so is there a way to fix it? Maybe my computer is dying? Not quite sure if this thread falls under networking either because it could a processor/hardware issue.

 

Well I'm on WinXP SP2, don't really want to remove it since microsoft is requiring it now to get updates. My computer has always been this way, even before SP2. Nothing is really hogging my CPU usage when I look at ctl+alt+del, that is what is weird. When I play games and some other programs it goes to 100% CPU usage, but from what I've heard it should never run at 100% usage for as long as it does. My main concern is why I lose connection when it does this. It is sort of hard to play a online game when you computer kicks you. Thanks for the suggestion.