I've seen this happen with people that run P2P programs or those that don't enable a firewall. There are some hardware issues such as a drive that fails "SMART" or a drive fitness test.
More about use could be revealing (P2P, IRC, etc.)
i had windows xp sp2 and about every 3, 4 weeks i had to reformate over and over for paste 6 months
its been pain,
and i had windows update always updated
used about 20 diffrent security applications.
my computer seem to be keep getting messed up
alot of times i had windows shut down and couple of times the ntfs.sys was missing but i cuoldnt replace it it says access denied...
im tryin on windows ultimate now...