configuration in Office stops and prevents using program

I purchased a computer with Office 2007 loaded on it and have tried to open
Word and Excel specifically several times. I get the message asking if I
would like to configure now. The first few times I used the programs I was
opening existing files to read them, so I clicked no on the configure now
message. The next time I opened Word I went ahead with the configuration,
typed in my product key, inserted the CD, and got the configuration window to
open. Then it stopped - the configuration bar never made it much past 1/3
progress. I can't use the program without canceling the setup, and if I do
cancel the setup, I can't use any funtions - all the toolbars and formatting
is greyed out.
Any help is appreciated!