Setup Error for Office 2007 Enterprise Edition. i bought a Office 2007 enterprise edition for

Question

i bought a Office 2007 enterprise edition for home users from Microsoft offered to my organization's employees. I started to install it now and it is giving me Setup error"
"Setup cannot continue becaue a required file is either corrupted or not available. Run setup again from the original source disc or download location". I tried to uninstall the program but getting the same error even while uninstalling it also (from Add/Remove programs). I even inserted the original disc with the software in the DVD rom. I don't know what else to do. Give me any clues if you can.

Thanksthe pc as me to give the 25-character product key