I have a two PC setup on a KVM switch (USB KB & mouse, VGA video). The first system is Vista Home, and the second is Windows 8.1.

If the Windows 8.1's video is not active (by the KVM switch) at night, it "undetects" the monitor, and reverts back to very low video resolution (1024 x 768), and generic monitor. The only way to bring back the usual display settings is to either reboot the system, or click on the "Detect" button in the display settings screen.

If the 8.1's video is kept active during the night, the video settings are kept unchanged (1920 x 1080), and Dell S2309W monitor.

This only happens during the night. If the Win 8.1's video is not avtive for prolonged periods of time during the day, this does not occur.

This also does not happen when the Vista system is not active during the night.

Any way to disable this behaviour? This also happened under Windows 8, before the upgrade to the beta 8.1.

Hi,

Have you enabled hibernation? It will occur if the driver cannot be loaded after resuming from deep sleep.

You can use the following command to disable hibernation for testing.
powercfg.exe /hibernate off

Meanwhile, please check if there is any log in Event Viewer.

Hi,

Thanks for the idea, I have enter this command line and has since not had the issue. I will report back in a few days.

Thanks