Well i haven't a clue as to why this problem appeared in the first place but i think you should be fine.To be on the safe side try to burn all your important files and documents to a cd, or put them on that USB drive of yours.You should do this every now and then anyways deanna as you never know what can happen to your PC.If you have a backup program such as Norton Ghost i suggest you make a backup of your whole HDD.
Cheers
Mikey