Running Slow after restart - Rhino 5

My Rhino 5 has become almost unuseably slow after a Windows update and restart. Also happened once before, but sorted itself out after multiple restarts, but no such luck this time. Nothing to do with file size as it is just as bad in a completely new file!
Thanks for your help!

Please go into Rhino Options > View > OpenGL and take a screenshot of that page.
I think I might know what’s going on.