I have decided to move my wife from Windows 8.1 to Mackintosh. I am running Yosemite on my workstation and it is completely stable. (See spec's). Both her system and mine are home built (see spec's in sig). The only difference between the two is the video card (hers is nVidia 640 and mine is nVidia 650).
I made a clone of my boot/system HD onto a new HD for her. I then installed Clover 2818 onto her new HD. Upon booting the HD with the system on my PC it works, video and all. Moving the HD into her PC and booting results in seeing video during Clover and the initial boot screen (Apple with progress bar) and then the video turns off (I lose video signal to the monitor).
I booted her system with a "recovery" HD I have that has Mavericks on it. I use this recovery disk to boot my system whenever I have a problem with my working install. Putting the recovery HD into her system and booting results in it working correctly - video and all.
So, it appears the hardware is working. It is "wierd" that her HD works in my hardware and not hers, and yet the two builds are identical. The only difference (other than the video cards being 640 vs 650) is possibly in the BIOS settings. I have checked those, but I will check again...
Could the flaw be in making a clone of my system, that OS X keeps a record of my video card and when it starts on the new hardware it doesn't notice it is a different card???
Any suggestions on tests I can perform or what might be going on here would be appreciated. I guess the next step to me would be to do a new clean install on her machine instead of trying to move a copy of my install???