I run both Visio 2003 and 2007 on several PCs. Switching back and forth works
fine -- you just have to put up with the minor annoyance or each version
"reinstalling" itself if you've been working with the opposite version.

Recently, Visio 2007 apparently hiccuped while reinstalling and it no longer
works. Specifically, it displays the "Preparing to install..." message,
starts, then issues the following message when I open any drawing:
"Attempting to use an incompatible version of visgrf.dll. Please re-install
visgrf.dll"

Copying visgrf.dll from another Visio 2007 system didn't solve the problem.
The real dilemma at this point is that the Office Repair function doesn't
solve the problem, nor does uninstalling and reinstalling.

How do I force an uninstall/reinstall or do as the message suggests and
"re-install visgfr.dll"?