I note you say “re-install” Office. This obviously suggests you already had it installed before. Office can get its knickers in a twist sometimes, because you may think you have uninstalled it, but there will still be traces of it left behind. You then try to re-install, but one of these remnants can screw things up.
There is a tool that fully removes Office (I don’t have a link, but someone else here, or a Goggle may find it for you).
You may be better to fully remove it (using the tool) then try again.
Before trying this, have you tried “detect and repair” from one of the working apps?
And a final thought, are you trying to run various versions of Office at the same time? This can also give problems (although I am managing to run 2000 and 2003 together, just!).