Saying it is an Win10 problem is a misnomer. It is really a Video Card problem that happened to show up for us with Win10 but it also happened to real late Win7 and 8 PCs with real new (at the time Video Cards). Your Vid Card is around 2012/2013 and 2/3 years before Win10 and isn't effected but what is an common problem by 2015/2016.
My RX580 is grayed out in game but able to be on by manual cfs2.cfg editing.

My RX580 is grayed out in game but able to be on by manual cfs2.cfg editing.
