The 2007 Microsoft Office system does not support upgrading from a prerelease version

OK, so my Beta TR2 of Office 2007 timebombed on me on Sunday there (should've known really given the last timebomb - ah well, you can't beat procrastination!)

Tried to install the full version of Enterprise and came a cropper once more
with the error:
"Setup is unable to proceed due to the following error(s):
The 2007 Microsoft Office system does not support upgrading from a prerelease
version of the 2007 Microsoft Office system. You must first uninstall any
prerelease versions of the 2007 Microsoft Office system products and associates
technologies."

just as Scott Hanselman did. I found this a really useful post but what happened me was that the uninstaller failed about half-way through leaving Office thinking it was uninstalled but not really.

I ended up discovering what was going on in the %temp%\SetupExe(20070304).log file (first mention of "Catalyst beta product conflict check failed." indicating it was product {30120000-0011-0000-0000-0000000FF1CE}-C (i.e. the main installer).

Anyway, I found the installer (via the registry - HKLM\Software\Microsoft\Current Version\Uninstall) to be sitting in my C:\MSOCache directory so reinstalled the product, selecting that nothing was to be installed on the hard drive.

After that, uninstalling Beta TR2 completed successfully and the RTM was ready to install... Phew!