Im running windows 7 on a fairly modern machine (8gb ram, amd fx-6100, gtx 560ti) and I notice that periodically my windows seems to just hang for a little while. Frequently this occurs after a cold boot and i start up five or six small to medium sized programs, but also occasionally it occurs during normal usage. Basically what occurs is the screen locks up, there is no keyboard responsiveness for a period of 30 seconds to a full minute - after a bit of patience, control is returned, but I'm interested in figuring out what is causing such lockups. I checked the event log and dont see any issues, and all i can see in task manager is a spike in cpu and memory usage right after this occurs.

Any tips on how to even begin to diagnose this? Thanks.