Your GPU may have hardware failure and need to be RMA'd or replaced.
Re: your comment http://superuser.com/a/948795/149636https://superuser.com/a/948795/149636, my similar problem was caused by a faulty GPU. I had to RMA it, and the new one works great.
[What I could never figure out was either my bad one went bad at the same time as I did my upgrade to Win10 from Win7, or Win10 is using some (bad) part of the GPU that Win7 wasn't. I didn't try any other OS with the GPU, sorry. I did not have any other indication that the GPU was bad before I upgraded. It just literally stopped working the same week I upgraded.]