Some programs not working after installing Office 2010

After removing Office 2007, and installing Office 2010, when a user tries to use a program, they get a window asking for the install DVD for that program. For instance, I have a user who tried to open AcrGIS Desktop, and they get the window asking for the install DVD.

Why would this happen? Could it be a possible shared dll or other file that Office 2007 and the other program used, and now that I’ve removed Office 2007, it removed a shared file as well?