I've never had to do this, but an approach that I'd probably persue would be to use Symmantec/Norton Ghost to create occasional disk images that would get xferred via Samba to a *ix filesystem. I'd try real hard to keep important data off of the M$ machine's local disks.
One way I have done it is to use MS's backup program to backup to a samba share on a freebsd box. MS backup will happily backup to a samba share. Then I just backup all that stuff using amanda.
I've used MS backup on XP Pro and w2kpro this way and it works pretty well for my needs.
-- Michael Perry | Do or do not. There is no try. -Master Yoda [EMAIL PROTECTED] | http://www.lnxpowered.org