"Bert Hyman" <bert@iphouse.com> wrote in message
news:Xns972F9F33EAC23VeebleFetzer@207.46.248.16...
> If XP encounters an unrecoverable hardware-related I/O error on a drive,
> does it mark that block (or whatever the smallest addressable chunk on
> the disk might be) bad, so that it won't be allocated to another file in
> the future?

No, it does not. You must run chkdsk /f /r in order to mark bad blocks.