I spend the evening hunting down why every time I run Office 2010 in my demo machine, it would first launch configuration... Always configuring...
After a few attempts at reinstalling that doesn't seem to lead anywhere, I decided to read the registry and see if there's some residue key that's causing problems.
While I didn't find the key, I did find a few very suspicious looking keys that it was requesting, right before launching into the Configuration Wizard (again).
For Word, Excel, PowerPoint... and most of Office:
Create a DWORD NoRereg=1
Create a KEY NoRepairNeeded. I don't seem to need to add any default values or any other values in the key.