I followed that link you sent me and have done the following and still have the problem:

Searched for 'Normal.dotm' & 'Normal.dot' could not find a single file.
There are no files in C:\Program Files\Microsoft Office\Office12\STARTUP
Tried renaming C:\Program Files\Microsoft Office\Office12\ADDINS to ADDINS.bak, still had problems
Tried renaming every directory in 'C:\Program Files\Microsoft Office' to .bak apart from Office12

Within regedit you should be able to find the startup path by looking at:
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\W ord\Options\“STARTUP-PATH”
This didn't exist.