My installation (Home Edition) is a bit messed up, all sorts of network files have gone pear-shaped.

So anyway, I decided to reinstall Windows XP (without deleting my data). I put the CD-ROM in, restart PC, boot from CD drive. It goes into Windows setup, then I press 'R' to repair Windows. It then asks which Windows installation I want to repair, and gives me one choice: unsurprising, since I only have one Windows installed.

Then it asks me for an administrator password - but here's the problem, as I don't have an administrator password! I assume it means the password on the administrator user account, but my admin accout doesn't have a password. I've tried leaving it blank, entering 'password', 'windows' or any sensible word, but no luck. It just says "invalid password entered 3 times: press enter to restart".

Any thoughts?