Go to another XP computer, unhide hidden files and copy the ntldr, ntdetect.com and boot.ini files to a floppy disk. Make sure that the boot.ini file is the same as yours for Home or Pro and if it isn't then edit it so that it is.
Put the floppy in your computer's A: drive and start up.
The floppy should use the ntldr to load the ntdetect.com and the ntdetect.com should find your hard-drive using the boot.ini file to do so.
You should then be able to reach the desktop and replace your ntldr file.
