In case you are having issues installing Office 2007 Beta 2 Techinical Refresh (B2TR)
For troubleshooting Office 2007 Beta 2 Technical Refresh (B2TR) installs, you might want to check out this Knowledge Base (KB) article.
The most common problem that I heard so far is the that to install the B2TR update, you need at least 2 gigabytes (GB) of free disk space.
Good luck!