I have had a dual system for the last few years, win 7 and win 10 on my desktop. This morning as I usually open with Win 7. When restart the pc to go to win 10, i heard the win 10 theme sound, but it was cut off and all i keep getting is a black screen. I checked msconfig and see both OS there with win 7 as my default in the Boot tab. After shuting down the pc and reboot and choose win 10 directly i get that sound again and this time a message that its aware that i have a problem starting win 10 and gave me the option to repair or try rebooting. I think the repair option is going to ask me if i have a win 10 disc, which i do not have, after all it was a freebee. Any ideas how to get my win 10 back?