I've tried everything. Coherence Mode is greyed out in Parallels 12 for Windows 10. I do not have an antivirus. (http://kb.parallels.com/en/121427) There are no other display adapters besides the Parallels Display Adapter (WDDM) that are installed. Parallels tools are installed properly. I've tried re-installing parallels tools in every manner outlined here: http://kb.parallels.com/112609 mobdro My setup: - I'm using a Mini DisplayPort to Dual-Link DVI Adapter to hook up to a 30" monitor. - Unplugging it doesn't allow Coherence Mode either. Thanks for any help!