Seems to be no further updates so not sure whether this solved the OPs problem. However....... I have the same issue. New system (i7-3.3 overclocked) which was delivered with a 500Gb Seagate Barracuda 7200.12 drive. System is fine. However I wanted a larger drive, so bought a 1Tb Seagate Barracuda 7200.12 and used Acronis 2012 to do a disc copy. Rebooting to new drive and system loads up fine but after some random period ( from a few mins to a few hours) I get the issue reported. 100% Highest Active Time. Resource monitor (after a short while) shows no active processes using the disc. (note: I tried both rebooting from the second drive and also swopping drives so the new one was first). All open Windows show "(not responding), although mouse still active and I can select application windows - just cant do anything with them. CPU activity also seems to be 0. After anything from a few mins to 30 mins I get BSOD (A thread or process crucial to.....) In my case at least, it would seem the actions menationed by PaulInGermany arent going to work for me.