How to reinstall xp over vista

[nitrotoad]

Hello,
here's the deal,my sister gave me a computer that was completely virues to hell-it had xp home editiion on it.i used my vista disk to wipe it but i cant use it because i used all my activation keys.so i burned a xp disk figuring i could use the key that came with the computer that was given to me.but when i put the xp set up disk into the CD and boot from the CD it wont work because vista overrides xp and it wont wipe clean for a new installation.im wondering if there is a way to remove vista so i can have a clean harddrive to install the xp back into it?..if i put the vista cd back in will i be able to wipe the HD without installing vista again?

 

[Dark Lord of Tech]

http://windows.microsoft.com/en-US/windows/help/install-reinstall-uninstall

 

[hang-the-9]

An XP boot disk will wipe out anything on the drive. Just tell it to format and create a new partition. Vista is not even running when you boot off a CD, so it has no say in "overriding" anything. Just make sure that the XP key you have matches the XP version you are using or the key probably won't work.

 

[nitrotoad]

Best answer selected by nitrotoad.