Hi to all, I'm new and I've searched for something similar without -apparently- any luck. I have a mp 3.1, with patched High Sierra, Win 10 Bootcamp (not anymore, tbh) 2x 2.8 GHz, 48 Gb of 667Mhz RAM, EFI GT120 and non EFI GTX970. I managed to get the gtx as a functional primary card with windows by disabling / uninstalling the gt120 and then by preventing driver install via gpedit. Everything worked for some months, then decided to give me the "Bad Handle" message before log in; tired of the continuous updates of win 10 and, de facto, unable to use the bootcamped win10, I erased, via Bootcamp tool, the partition and installed windows 7. The mess worsened, now I am completely unable to get my GTX970 working again. Tried anything. Reinstalling OS, disabling, physically removing the gt120.. no luck. Oh, and to add insult to injury, now I had two windows boot options. Thanks in advance for any help and sorry for the rusty english.