Windows 7: CPU usage keeps shooting up to 100% for no reason?

My PC has the habit of randomly and suddenly using up CPU to 100% for no apparent reason. My computer slows down to a crawl and I can't even shut down as it stays on the "shutting down..." screen. There's no rhyme or reason to it, though it never happens if I don't have the pc on for at least an hour or two. I checked the processes and there's nothing out of the ordinary running. I don't even know where to look. Help? This never happened when I was on Vista...

Hello, Welcome to the forums!
Could you please post a screenshot of your task manager during one of these High moments?
Also, what anti-virus are you using? That could be the problem.
~Jonathan

Hello to you too! I'll make sure to try to take one the next time it happens, if it will even allow me (even vlc and firefox dies when this happens). I'm pretty sure its not AVG. Nothing at all happens when its doing a scan and such. There's never anything in the task manager that indicates something is sucking the resources dry. Firefox is typically using up the most memory and svchost...

It's not usually the scans that bite you. It's memory leaks. AVG has been know to cause problems. It is not just my bias. I used AVG for a long time, till it developed a memory leak on my machine. Try uninstalling it and installing Microsoft Security Essentials. MSE works very nicely on Windows machines.

Ah I see. I'll do that right now (install MSE). Should I uninstall AVG too?

Edit: Oh, duh. Stupid question.

Yes, certainly. Always uninstall your previous AV before installing a new one. I don't think MSE will even let you install if it detects another AV.

I've been having this problem too. Sometimes it happens straight from bootup and the gadget I have that shows processor/RAM use doesn't even come up. I think it's been what's kept my login screen from coming up somtimes too. it just hangs at a black screen.

Sometimes it happens within 30 min or so after boot-up. When I've managed to get a task manager up, there's nothing to indicate a process that's maxing out the system. It might say '100%' at the bottom, but adding up stuff in the CPU column doesn't add up to that, even making sure to show all the processes, not just mine.

Most recently after booting up my Norton was turned off or thought it had expired or something. I downloaded AVG and got it to run a full scan and all it found were cookies.

To avoid confusion, please start your own thread... Thanks..

Nope, didn't work. Happened again while I was playing Fallout, 3 hours after start up. I couldn't even take a screenshot, nothing would work. But I tried to look for anything in the processes that could be doing it...nothing. This is getting tiresome...

Filll in your hardware specs and use the guide in my sig to update your drivers. Can you also post a screenshot of the msconfig startup tab and your installed programs?