Vista Enterprise on HP nx9500

I recently tried to upgrade my HP nx9500 with an upgrade license of
Vista Enterprise. I was previously running Windows XP SP2 with all of
the latest updates. After getting through the majority of the
installation (prior to entering the license info, etc), it restarted
and gives me the following error:

The computer restarted unexpectedly or encountered an unexpected
error. Windows installation cannot proceed. To install Windows, click
"OK" to restart the computer, and then restart the installation.

I subsequently restarted the system and it offered to restore the
previous OS (Windows XP Pro) which worked fine. I tried the upgrade
again several times, choosing to Repair the installation, a clean
installation on an existing partition (Windows folder renaming),
anothertime starting with a clean install on a new partition (killed
the old), etc.

Each time, I received the exact same message as above and upon
restarting the PC, receive the same error each and every time.

Any ideas?!?

I should mention that before everything, it did pass the Vista
compatibility test.