do you have at least 4gb or more of system memory installed on the motherboard ?
The low memory can create a problem like that , its going to happen with 2gb for sure , if you have 4gb it may will be ok may not , get 8GB ,that should be enough .
8GB system memory should fix your problem !
I go to try to put more ram to pc i have 2GB, i tell something when test it.
Edit:
Yes! it's for ram i need more ram i put 2GB and worked, with win 10 or 7 64b need 4GB for this RX 480 nitro 8gb.
With 7970, 290x, 5850, 6950... i don't need 4GB but with this new cards yes.
Tnx a lot for your help, this make me crazy and now fixed the problem!!!