I have the same problem. After doing a complete and full re-install of Windows XP and re-installing Office XP, it works for a day or two and then whenever I bootup the computer it opens up the installer to re-install Office XP. Help.
I have installed office xp (and a few 2003) on individual computers in a computer lab environment. When a user opens any of the programs, it opens up the installer - usually it opens up after "cancelling" the install, but not always. Is there a way to get around this annoyance other than leaving the CD in the computers all the time? Did I do something incorrectly when I installed Office? Most of our computers are NT with a few 2000. 2000 actually fails to open at times ...

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic