If the recovery console cannot find any versions of WINDOWS to logon to, you will have to boot from a DOS floppy to make the changes (if the drive isn't NTFS that is

)
Generally, boot.ini has a generic reference to the first partition on the hard drive like:
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS (or WINNT)="Windows 2000/XP Pro"
Sometimes you can get away with just entering the drive letter also.