Windows 7 freezes randomly for 30-45 sec, solved!
 

The Problem: Windows 7 randomly freezes for 30-45 seconds before returning to normal as if nothing has happened, regardless of application and workload. Complicating things is a total lack of error messages, Event Viewer logs, BSOD notices or any signs in Task Manager of an actual crash. Curiously, the mouse will continue to respond during these momentary hangs and actions are stockpiled until the computer resumes. Most frustratingly there wasn't an apparent trigger. After a grueling 12 hour stretch trying to find the solution, PCSTATS nailed down the fix to a a very specific Microsoft Knowledge Base Patch released just two weeks ago.

http://www.pcstats.com/NewsView.cfm?NewsID=85848