topdog

Another way
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.
Correct me if I'm wrong

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