Kevin,
The issue is not MM.Net 3.5. It's uninstalling 2.4. I initially uninstalled vs2005 and attempted to uninstall mm.net 2.4. That is when the error occurred. After unsuccessfully uninstalling mm.net 2.4, I went ahead and installed vs2008 and mm.net 3.5. The installs were successful. Just can't uninstall mm.net 2.4!

2nd issue:
I apologize, but I am new to .net and mm.net. I am having difficulty with your security classes in both versions of mm.net.(however 3.5 is now my immediate concern)
Both times, I created the Northwind database with Microsoft's install for the Northwind database. I then ran your MMSecurity.sql. Tables, relationship, etc were created properly in the database. (I created the security tables in the northwind database, not a separate security database) I set the flag in the Northwind CSharp sample project's app.config to turn security on and run the app. Login with the MM user and all is well. I then create a role. When attempting to associate a User with a role from the Lists menu in the sample app, a row does not get created in the UserRoles table.

Any idea as to what is happening?

Thanks,

Dwayne