OS X Yosemite 10.10.5 15-inch mid 2010 Wont work about mbpmid2010_gpufix HOT 8 CLOSED

Thanks for the follow up Julian. My computer died, the hard drive died. Before I could uninstall the program you mention I tried updating to Sierra, which ended up being a terrible idea. My computer entered an eternal loop(computer stared and attempted to install Sierra, before it could end the installation it crashed. And the process started again). So i decided to change the hard drive to another MacBook pro with the idea of installing Sierra there so I could then return it to my MacBook Pro 15’ (the one with the problem). Did that but error occurred. Black letters appear when turning on the computer (with the hard drive of my computer). After that Failed I tried other 2 old hard drives I had at home, but this time in my computer, the one with the problem. Both hard drives presented the same error: black letters when turning on the computer. I guess my computer was trapped between the two versions Yosemite - Sierra. It seems the problem of this is not on the hard drive but in other part of the computer.. cause now 3 hard drives presented the same error. I was thinking of buying another new hard drive and via internet installing OSX. But I’m afraid my computer will make it un functional (with the same black letters on start up). What do you suggest ? Can I still save my computer? Thanks for the help!

Julian, whats your PayPal account(mail)? the tipping website wouldn’t let me: error. Thanks