I has in practice 4 Gb gpus on WIN10 and mined without problems as I told early

But maybe your monitor is connected to the motherboard video... Not on the mining card...
No, my monitor connected to the first video card because my processor no has integrated video
What and where are you mining?
I tried to mine eth in ethermine and i tried to mine in nicehash - a lot of problems and restarts... And some of mine RX480 are with a speed 7-8 MHs
I mined ETC on ethermine ... on RX470 , RX560, RX570 4Gb and all nice , don't overclock its too much cclock 1000 MHz , mclock 1800-2000MHz vddc 850-1000 mV