Sorry, Dave, but that is just not true. Although it is theoretically true,
in practice it is possible to do a clean install of Vista on a bare drive
using the installation media with an upgrade key. Even Microsoft documents
this.
Here's how:
1) Boot with the Vista install media (contrary to your protestations, ALL
install media for Vista is bootable. In fact, there is NO SUCH thing as
"Upgrade media for Vista", since ALL versions of the OS are on a SINGLE DVD,
and your purchased version is installed with a key which is only valid for
YOUR purchased version.
2) When the Installer asks for your key, DO NOT ENTER IT!!!!
3) Delete the previous Windows partition, then recreate a new one and format
it, then point the Installer to that partition.
4) Continue the installation until you are at the Desktop.
5) With the Vista install media still in the drive, start the Installer from
within Vista, and when it asks for your key, ENTER it this time. Tell the
installer to do a custom installation (that will perform a "clean"
installation), not an express installation (that will perform an in-place
upgrade)
6) Repeat steps 3 and 4.
This is possible, because a clean install with upgrade media has ALWAYS been
possible with XP, though it has not been well-publicized. Now there IS no
"upgrade media", only "upgrade keys".
When Vista is installed the first time, then reinstalled a second time, the
Installer sees the existing installation of Vista, and assumes that it is
valid. This is actually ok, since Vista->Vista is a valid upgrade path. If
you enter the install key the FIRST time, then wipe the drive, the installer
will protest when you try to install, since it will find no valid
installation of Vista to upgrade. However, if you fail to enter the key
the first time, Vista will install as a TRIAL version. The bug is in the
Installer's accepting a TRIAL version as a valid upgrade base for the second
installation.
Either Microsoft intentionally left this huge hole in their Vista media, or
they overlooked a BIG bug. I will bet that this bug will be fixed very
soon.