Last night I took my pooter out of sleep mode and it rebooted and went right into check disk ( Windows 7 /64 ). Anyway I noticed it started this " Deleting security file and replacing with default." This went on for about 15 minutes with thousands of so called security files being replaced. I went ahead and did a forced reboot and stopped it, but I was to tired last night to do a format...lol. I have run into this using Vista and let it run it's course and it crashed my OS so bad I had to do a complete reinstall.....there is really no reason MS has given for this but I was wondering if any of you guys have run across this mess yet.Sometime this week I plan on doing a full format cus it kinda of bothered me to see something like this happen..Mike