Hi Adam,
Sorry it didn't work out the way it should. Now that you've cleared everything out and got a clean install, why not try it again just to prove it does work. I can understand your partner's apprehension, but there really is no need.
As far as Office 2007 is concerned, I can't really help. I tried the beta and how have the trial version and they both installed without a hitch. All I can suggest is that you remove the existing version with the Windows Installer Clean Up Utility. If it's not already on your machine you can get it from
here. Run the program msicuu.exe. It's in C:\Program Files\Windows Installer Cleanup. Then reinstall 2007.
Once again, sorry we weren't able to solve your original problem.
Regards,
John.