Digital photos on external drive have gray bars

I doubt that the problem of seeing the gray bars has anything to do with your present computer operating system, amount of RAM, etc. Easy to test that by opening the photos on another computer. My guess is that you'll still have gray bars. Sounds like a file corruption problem to me. A recovery process could work but is usually pretty expensive. One suggestion already given - try to use a photo program like Photo Shop to doctor some of the photos - is a good one. Rotten problem. I wish you the best.