Normally I don't waste time on Windows but this might actually help someone.
A few weeks ago my wife got me a new dell laptop and it came with Win 7 and a free trial of office 2007 pre-installed. My wife has a laptop with the trial version of office on it as well. We decided to buy Office since you can install it on 3 machines and she needs it for work. Hers is working fine but mine was a nightmare after 2 attempts to uninstall office, the uninstaller said I had to have the disk which I didn't have since it was pre installed, needless to say I found the answer on Microsoft's website. Well after a complete reinstall of office I discovered every time I try to open a document it ran the installer program. I found a LOT of post's in forums and such looking for an answer. I tried everything I saw and nothing worked so I took a process viewer I have and installed it to see exactly what processes were running and when so I could track it down "guess Microsoft can't figure that out?" anyhow it was the setup.exe from the original Office trial prog in the Microsoft shared/office12/office setup controller file. I renamed the file setup.exe.old and now it magically works fine. This was after about 3 hours of wasted time reading and trying everything I could. That my friends is why I mostly stick to LINUX things don't "just Run" unless you execute them.