Win10 Home on iMac/El Capitan/4Kdisplay I have a second VGA monitor hooked up to the iMac. I get perfect dual display functionality when operating in OS X. When I open Win 10 under Parallels and run in Fulll Screen, I can no longer move a window to the second monitor, even though the mouse cursor moves back and forth just fine. Instead, the Window window will slide under the right edge of the left monitor, then do the split pane thing that is a "feature" of Windows 10. I am not sure if there's a Parallels setting problem or I need to turn off some Windows "feature." I didn't have this issue with Win 7 running under Parallels 10 (and my iMac was on Yosemite)
Thanks. I am on Parallels 11 so option 1 doesn't apply. Option 2 and 3 didn't work. I tried them again, still no go. However, when I exited Coherence mode, I am not able to use both monitors for my Windows display. Starting and stopping Coherence mode seems to have healed it. STrange....