Office 2007 - Hang during Install

I upgraded to Vista Ultimate from XP. When I did, I had to use a "clean
install" version, as the upgrade version kept halting at 21% on "expanding
files". Everything seemed to be in order, then I tried to install Office
2007 - which worked fine on XP. The install gets to 99.999% complete, then
just hangs there (so far about 7 hours). If I try to close it, it says "Do
you really want to exit setup" - so something is happening. Anyone else with
this??? Some things any helpful solver might need to know... 1) This is a
download edition, that I received the key to at an official Microsoft Launch
Event - not a DVD version. 2) The download edition worked fine when I
first installed on XP. Any suggestions or help would be appreciated.