Weird hard drive problems

[Kyler999999999]

Ok so basically me and my dads hard drive just messed up and I've run out of ideas. Mine stopped working randomly one night, it still gets detected by my computer but doesn't boot and gives me the pxe over IPv4 and IPv6 errors.( I have windows 8)

I then started using my dads computer where I used to have mine set up, but I couldn't really do anything on it because it doesn't have a very good graphics card / processor so we tried to see if my graphics card could run in his computer, it didn't really work but his computer would still boot up and everything was there but when I put his graphics card back in and put is back to his computer desk it stopped booting up and started saying his hard drive wasn't working when we did the tests, so I was wondering does this sound like a power surge in the outlet by my computer desk or did the files get corrupted when we switched graphics cards? Also since both of our desktops aren't working right now how would we go about trying to recover files back from the second broken hard drive? Is it even possible?

 

[Kyler999999999]

Also this is probably pretty important too, my hard drive can pass the test but his cannot, he is also on Windows 7. At this point I'm mostly interested in trying to recover what's on his hard drive because it has important stuff on it so if anyone could help that would be awesome