I have dual boot windows 10 and windows 7 setup. windows 10 is the main system. windows 7 is a hard drive taken from old broken laptop. I used bcdedit to set it boot up. windows 7 banner start up for 2 seconds then system would power off and restart. I wanted to see what was loaded on the system so I used windows 7 repair disc to make it start. The repair disc 'says could not automatically repair the system.. Then I restart the system. now the windows blue flash windows icon would come but then screen turn black, system stay on, nothing happens, hit any key on keyboard, push power button on computer case, screen still black. the power button on computer case would not turn off system. this stay long time, then the blue boot menu come on. windows 10 would load slightly slower than usual. how to fix this issue ?