So if anyone (Zach) is interested in how that software uninstall went, there were some definite repurcussions. Outlook started crashing when the client tried to send an e-mail. I'm not sure why this happened, but I ended up having to reinstall the entire Office suite to give the executable the resources it needs. That didn't repair the DLL issue, though - the registry was still telling it to expect to see the file. But I found out how to disable that from within the software, so everything works and starts clean.