I recently imported a Parellels Windows 7 Professional virtual machine to Fusion 8. The conversion went well.

Now I would like to upgrade my Win7 Pro to Windows 10. When I click on the "Get windows 10" icon in the task bar, I get an error message returned that says I cannot install Windows 10 because of the presence of a "Parallels Display Adapter (WDDM)" which is incompatible with Windows 10.

However, when I look in the Device Manager there is no Parallels Display Adapter and I have already uninstalled Parallels Tools (I did that before converting to Fusion).

I'm wondering if there is some vestige of the Parallels Display Adapter somewhere in the registry (or somewhere else). 

How do I delete a device that doesn't show up (yes, I have tried showing hidden devices in Device Manager)?  Is there a workaround for this issue?