Simple answer - you can't.
It's a case of backing everything up, noting all settings and components and doing a complete format and re-install.
Given this situation, I would buy a new hard disk and an external USB caddy.
Put the new HD in the laptop, and the old one in the caddy - you should then be able to read the old one without any problem after the clean install, so all the data, etc. will still be accessible.
Also worth trying is the User Settings Migration Wizard - though I'm not sure if it is on the Win2K CD. But you may be able to download it from MS.
SD