(Precious problem in 'Windows upgrade Failure')

I would like to know what are the possible causes of hard disk failure after an OS upgrade.
Besides the need of RAM.
I have recalled recently that I have seen a lot of 'old' computers; mainly computers that barely surpass the 'the recommended specs' for a given OS work fine. Slow but fine.
I have a P4 1.8 256 RAM, most of the people I have consulted says that my computer should run Windows XP without problems, since the minimum requirement according to 070-270 is hardly 300 mhz and 128 RAM I am puzzled by the hard disk failure.
When downgraded form the previous OS (Win2k) it was working perfect again. I have tried several time to upgrade ti to Windows XP, but after a few reboots, the hard disk fails.
Now, I would not like to replace the hard disk needlessly since it works fine with win2k, if anywone could pinpoint the problem, or perhaps give advice please do.

thank you