What version of Office do you have Installed ?
Do you have the Install Disk >?
Ok best thing is a clean install
You will not lose any Data
First click the Link below and under method 2 download and install and Run the Fix IT
A black box will open > and let it run it will remove office
Then Restart the Machine and Insert the disk and install
Let me know any issues
Now please click the Smiley Faces and Submit
Come back any Issues
This is usually an Issue with the .Net framework
Did you have any other Versions of Office installed like 2003
Can I remote on and Have a look ?
It could be many things i am afraid , there are a quite a few issue that can cause this