Well hopefully someone can figure this out. Was running the GTX970 in my 5,1. Was running perfect yesterday. Turned it on this morning & it stats in bootcamp?????? Go to bootcamp control panel in windows & restart in OSX. No, it restarts in windows again. So, take the 970 out, put in my AMD 7970. Same thing. Boots to windows. So I go to bootcamp control panel, select Sierra disk, apply, OK hit restart. Starts in windows again. So..........put the old trusty 120 in and it starts in Sierra as it should., go to preferences & select start up disk, Sierra is already highlighted, lock preferences. put the 970 or 7970 (both pc cards btw) back in, goes to bootcamp. Driving me crazy. Any ideas???????.