This happened a while ago, but I'm just now getting to this due to other reasons. On March 4, 2012, I started my Xbox to play some COD:MW4. It started up and then said there is an update. So I updated it and the game loaded up. I hit start and then it tells me to sign in. I look for my Xbox Live account and I don't see it. I see a couple of extra player profiles that I previously created for when ever friends stop by, but mine is not visible. I decide to go ahead and restart the system thinking the update required a restart. The game starts up with the game and asks me to sign in. I look for my profile, but none are visible. I restart the system once more and then the xbox asks me to create a profile since there are no profiles found. I skip that and go to the system settings to check on the hard drive and it states my hard drive is unformatted.
I've removed it, reinserted it, and cleaned it out with air to no avail. As I looked through the forum topics searching for a solution, I noticed that there are many people that have run into this problem as of lately. Seems to be a peculiar coincidence. Or maybe it just happens all the time. Yes, I know that reformatting is an option, but I don't want to lose the saved data. Anybody have any luck with that as of yet?