Nope reinstalling because I mnight be going 64bit.Hey Deadpixel, haven't seen you around for a while
It's perfectly safe to reinstall Vista - no harm done.
Note that Microsoft has changed the Windows Vista code so that you cannot actually reinstall Vista the way you could XP to repair a glitch or fix some missing files. If you want to "reinstall" Vista, you'll have to install it anew.
Vista is on my 160GB hard drive. I am doing quickfat32, when I reinstall Vista, so everything will be wipped.Not even then. When you reinstall your old bootloader will be preserved (if you don't format your boot drive).
The XP entry will still work. Just you'll have a new one for x64 now