I was having problems with a small boot issue and USB hub not being recognized anymore. Solved the USB hub issue by unplugging EVERYTHING including power cord. Let it sit for 10 seconds and then boot up. Not sure how that solved the USB hub problem. Basically, USB keyboard and USB mouse worked one day and next day the USB hub that they are connected to showed up with Unknown Device and code 43. Windows 7 problem? This is the second time I've seen this issue happen. First time was on my father's HP desktop and second time is on my personal build. Never did figured out the cold-boot loop though.