boot from xp cd (press del or f2 to go to bios, change boot order in bios, put cd to boot first )
when in Windows XP setup menu press the R key
Press the 1 key and then enter.
If you have a password type it and press Enter, if not, just press enter.
U have to copy 2 files.
(you can also backup these files, where U want)
copy e:\i386\ntldr c:\
copy e:\i386\ntdetect.com c:\
you'll get a confirmation.
If not, it's possile that U have to use the expand command, but I'm not sure...