I have a very fast custom built PC with 8 GIGS of RAM however sometimes my CPU usage starts hovering around 25% even though there are no processes using memory in task manager. This is causing a problem when I try and play games it makes the games lag really bad. It seems like this happens randomly and usually goes away when I restart but now the restart doesn't work.. it's still doing it.
I'm using Windows Vista Ultimate 64bit
I can't for the life of me find out what's causing this lag... it doesn't look like my AVG is running anything either.
You've got some software conflicting, I'm pretty sure. Could also be a bad driver. I had that happen to me a few years ago as well and couldn't positively figure it out either. But I seem to recall uninstalling software until I found the conflict and CPU went back down. (but I don't remember for sure)