why i get OCing failed when i am not OCd

guys as many as u know about a month ago i said when i turn my pc get an error that itsays overclocking failed and i was @ stock.
it has 2 options one was go to bios and the second was to load defaults and i choosed defaults and now when i turned my pc
 
i did , and now when i turned on the PC , it said CMOS.... ( i dont remember ) failed , press F2 to restore default and it came to windwos selection , i choosed xp , then it gave and addres (c:\...)and said that this was not found , please reinstall this file , then i restared and choosed vista and i didnt have problem , then i again restarted and choosed xp and surprisingly it came to xp , and i dont have problems now (well at least for now ) so what do u think?

btw , thx