I have a setup with 3 monitors.
Whenever I press Win+P and choose "PC screen only", Windows keeps playing an annoying sound every 5s.
When I look in the display properties or device managament, then it seems that Windows keeps 'losing' the secondary monitors, and auto-detects them again after a few seconds, when the device is in standby.
When I turn the monitors off, everything is fine.
But that's not a solution, because the buttons are pretty hard to reach, and I would like this to work instantly.

I just re-installed Windows yesterday. Before I remember that I had somehow solved this issue, but I can't remember how.

Please help!

I tried the suggested "TMM" "UseIViewHelper setting in registry, but it didn't work (even after a reboot). I also looked in my display driver's (AMD R9) tools for a setting to turn off monitor-auto-detection, but it seems the new Radeon tools don't offer that setting anymore.