I'm posting "vista uninstall" solution for the 3rd time
1. Boot your computer in to Windows XP.
2. Go to ?Start? and ?Run?. Type in ?e:\boot\bootsect.exe /nt52 ALL /force? (without quotes, and replacing e: with the drive letter of your Vista DVD).
3. Restart the computer, and you will notice the boot selection menu is gone.
4. Format the partition/drive where you had Vista installed.
5. Remove two files (Boot.BAK & Bootsect.BAK) on your XP drive?s root folder (C

, these were backup files of your previous bootloader, now no longer useful.