Uninstall
After playing around with Vista for a few days, you may want to remove it
from your system, and reclaim the hard drive space. Microsoft has made this
step very simple as well.
Boot your computer in to Windows XP.
Ensure you have the Vista DVD image emulated or in the DVD drive.
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).
Restart the computer, and you will notice the boot selection menu is gone.
Format the partition/drive where you had Vista installed.
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.
Optional: Restart to ensure it still works.
Use your partition software to merge your partitions together.
And now you have returned your computer to its previous state, without Vista
and without the new bootloader. If anyone has any issues, please post it in
comments and I'll try to resolve it
http://www.istartedsomething.com/200...-boot-with-xp/
"Airman Thunderbird" <> wrote in message
news:. ..
> I've tried Vista installed on my XP machine as a dual-boot. Okay, tried
> it, now I'm ready to dump it. Is there an easy way to go back to my
> single-boot XP, without starting over?