OK, I've installed Vista a couple of times (Beta 2), and ended up with a
customized boot menu (courtesy of Microsoft), that stays put even after the
hard drive that Vista was installed on is formatted. This happens when you
do a custom install on a computer that is already running Windows XP. When
you boot the computer after formatting the Vista partition, it defaults to
Vista (not very helpful, as Vista is GONE), or if you press the down key
fast enough you can boot an "earlier version of windows" (in my case,
windows xp)

Got tired of hitting the power button, grabbing coffee and coming back to
the computer to see the error message on the monitor. (because I wasn't
there to tell it to boot the "earlier" version of windows)

Did the google thing, but nobody seemed to have the right answer (that I
could find), though a few were close. So here is the proper procedure,
spelled out in no uncertain terms.

NOTE: You shouldn't have any problems with this procedure, if you follow
directions well. HOWEVER, I am telling you (not suggesting it, TELLING YOU)
to back up all data files from your hard drive to external storage, such as
DVD or CDR media or a USB memory stick, before you begin this procedure.
The chances of your C: drive not booting after this procedure are greater
than zero, so be prepared for disaster, in case you are extremely unlucky.

Boot your "earlier" version of Windows (ie, windows XP)

Fire up Windows Explorer. Set it to display all hidden and system
files/folders.

Do the following in this exact order:
Go to C:\ and find bootsect.bak. Rename it (like bootsect.vis), or just
delete it.
While still exploring C:\, find boot.ini and rename it to boot.vis
While still exploring C:\, find Boot.bak and rename it to boot.ini
While still exploring C:\, find folder C:\boot and DELETE that entire folder
Reboot

Now you should see JUST windows XP starting up, with no boot menu
howing. -Dave