Win explorer not working after DOpus Uninstall

I tried Directory Opus which I found pretty good for use at work but couldn't get my boss to pay up for so uninstalled it. Now when trying to open folders I get the OpenWith prompt come up like you get with an unassociated file. I can select Explorer as a one off but not set to open everytime with explorer. Any ideas how I can get explorer to work properly again.

The uninstaller should have removed the Explorer Replacement registry settings but if it didn't you can do it manually via a simple process:

[How to manually remove Explorer Replacement settings)