Upgrading to Office 2007 from Office 2007 beta 2

Last night I tried to upgrade from Office 2007 tech refresh, to Office 2007 RTM and received the following 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 associated technologies.

Correct the issue(s) listed above and re-run setup.

The online read-me that can be found here, helpfully informed me that:

The Office 2003 Web Components feature installed with Office 2007 Beta2 causes the Office 2007 product to block its installation. Users should use Add Remove Programs in the Windows Control Panel to Remove the Office 2003 Web Components, and then install the final Office 2007 product.

I searched through Add Remove Programs and could find no sign of the Office 2003 Web Components, so I installed Office 2007 and then downloaded, installed and un-installed the web components with no luck.

At this point I started searching around and found this article that explains that the error actually refers to the following much more comprehensive list of software:

This issue occurs if either of the following conditions is true:

• A beta release version of a 2007 Office program is still installed on the computer.
• A component from the beta release version of the 2007 Office suite or program is still installed on the computer.

You must remove all beta release versions of the 2007 Office suite or program from the computer before you install the original release version of a 2007 Office suite or program.
Additionally, this issue occurs if any of the following items are installed on the computer:

• 2007 Microsoft Office Add-in: Microsoft Save as PDF or XPS (Beta)
• 2007 Microsoft Office Add-in: Microsoft Save as PDF (Beta)
• 2007 Microsoft Office Add-in: Microsoft Save as XPS (Beta)
• Microsoft Expression Web Designer Beta 1
• Microsoft Expression Web Designer CTP1
• Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats (Beta 2 Technical Refresh)

Interestingly this list doesn’t mention the Office 2003 web components.

Anyway Office 2007 RTM still failed to install, giving the same error. 

Finally I came across the Windows Installer CleanUp Utility, which I ran and discovered that Installer files were still on my machine for several of the uninstalled Office 2007 components even though there was no evidence of them in Add Remove Programs. 

After deleting them using this utility Office 2007 seems to have installed.