It's showing as healthy, both drives appear in the top part on SI BIOses when this is so. You will need the driver to F6 when using an XP CD though. I would have put this down to a corrupted registry, which you could try rolling back (
http://www.winternals.com/Products/R...r/Default.aspx) or try making a WinbootCD (PE type disk) and booting from it and using the registry rollback tool.