I went into "Help and Support" on my computer and it said you can't
uninstall vista. hhhmmm.
You can't uninstall the operating system you are running from within
the operating system itself. That's true, not just of Vista, but of
all operating systems. Trying to do that is like sitting on a limb of
a tree while you're sawing off that limb.
The way you uninstall Vista is to format the drive. If you want to
uninstall and reinstall, boot from the DVD, then choose format, and
then reinstall.
Note that that means the loss of all your programs, data, etc. Be sure
you have a backup of your data before beginning, and be sure you have
the installation media for all your programs, which will have to be
reinstalled.