I am running Win 10 on my iMac using Parallels 14. The latest Win 10 upgrade resulted in a flickering screen. The advice in the pop up said increase graphics memory to 512Mb. I stopped the virtual machine and then changed the drop down selection in control centre to 512Mb. On restart the Windows screen went black. I managed to get back in and stop the VM and reset the display memory to Auto for Retina. On restart I still have a black screen where Windows should be. The Mac applications are running OK. I have tried everything else I know but no joy. I am afraid that I might screw up the Mac altogether if I carry on blindly changing settings. Anyone got a fix for this scenario?
Pete
Pete