When I right-click the Emperor.exe, and select "Properties", then "Compatibility", I find that "Disable Visual themes" has been ticked AND GRAYED OUT, meaning I cannot change this. And the same goes for the shortcut.
Is there a way to make that setting accessible?

It's perfectly possible that I'm missing something basic about Windows settings, but with my old disk-based version, this issue does not exist. It plays perfectly fine on my Win7 system without that setting.

Thanks in advance for any assistance that I might recieve.