Here is sequence of events... 1) I started hearing an occasional buzz noise from laptop (in general area of fan). It will come on for a few seconds and then stop. Seems to happen when I am on battery and not on AC power. I was also hearing it when I shut down the machine - on either battery or ac power. 2) Suddenly, computer won't boot. I power up and wind up at the screen giving me option for safe mode, boot normally, last good config etc. No matter what I select, computer loops back to this screen again, so I have no safe mode or system restore. 3) Using shadow protect, I restore my c partition. (I'm thinking there is some sort of corruption problem. Computer boots up normally for a few times and then goes back to doing what it was doing in #2 - showing that screen again. I have xp with all updates. Any thoughts on this? I'm thinking a defective hard drive, because it seems to work okay temporarily after the restore. Thanks for your help.