This is the 2nd time I have had this error in the last 3 months. The first time I formated the hard drive and re-installed windows XP with no problems. This was after having removed the hard and connected it as a slave on my other pc, virus scanned it, with no errors showing. My system was fully upto date, running fine, then today nothing. System is displaying same YoYo error at the startup page. So annoying. I have Flashed the Bios, as recommended on other links, but this did not change anything. I really don't want to re-format, as ultimatley this appears to only be a temporary solution. Personally this YoYo thing looks like a virus, but if it is, its in the motherboard on not on the harddrive. Anyone got any ideas what I can do? gnclarenmax

http://housecall.trendmicro.com/ To get rid of it. No it is not in the Motherboard. Get and use a good anti virus program.

Hi gnclarenmax, This is master boot record virus (MBR) and you cannot get rid of it by formating your hard drive. Read this link to get your solution. A infected user like you had same problem and got solution.! Link: http://forums.techguy.org/malware-r... Gud Luck!

If you fail to get solution by trying above link then, the solution to the problem is to ghost the infected harddrive to a clean drive. this will get rid of the yoyo/Y∞Y∞ virus. then you can ghost back to the original drive which will then boot with no problems at all. Hope this solution helps anyone who needs it.

Thanks for those comments... I have reinstalled / repaired Windows XP, which did not fix the problem. Using the Windows XP repair tool, I did "FIXMBR" and "FIXBOOT". All of that did not fix the problem. Addi, I don't have a spare clean drive large enough to ghost the offending h/d so I think that option is out. I followed the link you provided, but it seemingly does not end up with a positive resolution before the thread ends. I talks about installing Linux and using Grub to clear the MBR, which gives a blank screen, so no MBR. Then reinstalling MBR with the Windows XP disk, but the "YoYo" message appears again. If it is in the MBR, it appears clearing it with Grub, then reinstalling Windows MBR does not work. I am at a total loss now. Again, I have looked a numerous threads, all of which talk about having done the similar things, but everyone ends up formatting the H/D to get it working. There must be another way. I don't understand why AVG or Norton don't pick anything up on the drive. Plus, what the hell is causing this YoYo error? gnclarenmax

I think I have seen this and the only fix I found was I used PartitionMagic to convert the NTFS partition to Fat32 and that fixed the problem.