ERROR Message During Setup of Microsoft Office Ultimate 2007

Okay this is not a trial version. I received an error message during setup of
a free trial so I thought I'd pay for it since I have to have it for school,
and was hoping it would work. Well it doesn't. I paid for it online so it
was a download and during the install after I type in the key code it says:

"Microsoft Office Ultimate 2007 had encountered an error during setup"

Same error message minus the trial wording, as before. Now before a nice
guy named Peter I believe posted to my trial message and told me about some
helpful hints I could do. I do those, which was like 4 pages. I deleted
everything from the registry files it told me to delete, changed the file
name of a few, and moved a few folders around. Still error message.. PLEASE
Help me.. This is really getting me to the cursing stage now since I paid for
it, and its still not working.