1. Bootup with the Windows XP/2K/NT CD inserted (or with the floppy Setup disk set)
2. Select the Repair option (select R at the Welcome Screen in XP/2K)
3. Press 1 (presuming you have just one XP installation)
4. Press Enter for your Admininstration password (it's blank by default)
5. Now rebuild Boot.ini by typing in
- select the Windows XP, 2K, NT in Add installation to boot list
- answer Windows XP Home (or similar) for Enter Load Identifier
- answer /fastdetect for Enter OS Load Options
Optionally, you can then type in
to view (but not edit) the contents of the new Boot.ini.
6. Type exit when finished. Remove the CD.