If you run setup, eg, boot from the CD and pick 'New installation' instead of repair(which gives the recovery console). Then F8, then it examines your disk.
You get asked again if you want to install or repair - this time choose repair.
It runs like a fresh install including asking for a new admin password and network set-up.
All your settings and installed programs are preserved, only windows updates are lost - and your SAM and services settings. They are all returned to default - all settings are.
I have used this to fix all kinds of problems from corrupted registry (usually works) and bad Windows drivers.
But, XP is not easy to get into, is it? No going DOS and retrieving .dat files.
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Another note: I have the SP2 integrated into my WINXPVOL_EN and use it to install. Don't know if this would make a difference though. I only have Word, Excell, and Access 2003 so not much to conflict with SP2 here.
This is what I did:
http://www.theeldergeek.com/slipstreamed_xpsp2_cd.htm
Makes about 550 Mb disk, lot's of room for extra utilities.