I set up my first Windows VM on my new M1 Max MBP the other day, and for better compatibility with old games I went searching for a way to lock the VM's screen refresh rate at 60Hz. I was unable to do this anywhere in Windows settings, in every place I know to look 120Hz was the only option available. I read somewhere that Parallels just passes the host refresh rate through to the guest OS, so I tried lowering it in macOS System Preferences. Weirdly, even with the Mac at the lower rate Windows continued to run (or at least reported it was running, I didn't confirm) at 120Hz, even after I restarted the VM, relaunched Parallels, and rebooted my Mac. So I reverted the Mac refresh rate to "ProMotion" (120Hz) and rolled back to a VM snapshot I'd taken before beginning this process. What surprised me was that once I did that, Windows was locked to a refresh rate of 60Hz! I have no idea how or why. Unfortunately, now I don't have a way to put it back the way it was. I confirmed my settings in System Preferences and rebooted the Mac. Windows reports that "Generic PnP Monitor and Parallels Display Adapter (WDDM)" only support 60Hz now. When I created this snapshot it was still 120Hz, and I have no earlier snapshot to roll back to. It looks like it's stuck like this. Full disclosure: Before lowering the macOS refresh rate, I'd been experimenting with Custom Resolution Utility inside the VM. I don't really understand what that tool does or how it works. I was careful to create my snapshot before messing with it, so I could roll back if anything went awry. It didn't appear to work at all; after all my changes Windows still reported 120Hz. Then I went did the stuff I described above. Is it possible that CRU made a change to the VM that persisted after snapshot rollback? Or is that a red herring? Can anyone help me get my VM to use 120Hz again? Bonus points if you know of a way to toggle between refresh rates at will, for those old games that need it.