Windows Automation from Vb.net module in Access

I have created a nice tool for my company which runs Igor from within an Access 2007 database. Most computers are using Access runtime but it works well. The modules to open and run commands in Igor were adapted from the routines included in the Igor excel example. However, I have one user for which these routines won't open or connect to an instance of Igor.
I don't know what settings he may have that would prevent this from working.
Try uninstalling and reinstalling Igor. The OS uses registry keys that the Igor installer registers to find Igor.