Unusual one here. Our Church has two epson projectors in separate areas each is connected to a laptop in its respective area so both are connected to independent systems. Both projectors work fine when connected to the machines under W7. An upgrade to W10 sees the projectors power up and work for about 3 seconds when Windoze then decides that the Projector is no longer connected and reverts to the laptop display. Both projectors are connected via VGA cables to their respective machines. However, mr Google would tend to indicate that this is not unusual and an issue with HDMI as well. We have yet to climb up to the projectors (ceiling mounted) to prove the cables, however, as I said earlier, I'd expect a signal loss (long cable) or faulty cable to present regardless of the OS used. Windoze 7 does not suffer any of this. W10 works with a normal dual monitor set up so the only problem appears to be the projectors. Can't seem to determine if the problem is device (Epson) specific or if it occurs with all projectors.

The questions that spring to mind here:
Dodgy cable: Why only with W10
Signal loss: I'd think that W10 was more tolerant of this.
Projector Firmware: Why only W10? We have two projectors of different vintages so probably not.
Windoze 10: Drivers - again, if this were the case, why only with the projectors.

Both lappies are ToshiBah running AMD chipsets.

Anyone come across this? Have you found a solution under W10?