Der er 2 forklaringer,A og B som sikker begge virker.
A:
Dual-booting with vista can be a little tricky to remove because of the new bootloader.
Playing with dual-boot systems has killed many people's hard drives. I would suggest massive back-ups before you try to remove part of a dual-boot system. If you mess up, you might be unable to boot to any of your partitions. You do this at your own risk.
Here's the basic steps you need to do:
To remove the Boot Manager loader from your primary partition, use the BootSect.exe utility found in the Boot folder of the Vista DVD
Use option /nt52 to restore the ntldr loader
Use option /nt60 to restore the BootManager loader
Editing the menu options in the Boot Manager when starting your computer is no longer available through the file boot.ini
You have to use the BcdEdit.exe tool to acomplish this task
B:
1. Backup, backup, backup
2. Reboot and Boot to your XP CD-ROM
3. Start the Recovery Console
4. Run Fixboot
5. Run fixmbr to reset the master boot record
6. Exit the Recovery Console
7. Reboot
8. To remove the extra entry, edit the boot.ini file to remove the "Microsoft Windows Longhorn" entry.
9. Format Your Vista Partition
VH Palle Hansen