Question : Windows installer when trying to open word

I have a PC running vista busness with office 2007 installed. This has been runninghappily for months. Today, however anytime I try to strat an office app the installer starts and I cannot open the app.
Anyone know what is up?

Answer : Windows installer when trying to open word

Usually happens when an application component is trying to be installed.

1) insert office disc and go through the installer. This should only have to be done once.
if this doesn't work:
2) repair office in add/remove programmes
or
3) add all office components
and then if that doesn't work
4) uninstall/reinstall