Reinstating macOS on Late 2011 Macbook Pro
My (model A1297) Macbook Pro failed last week and I had to install a new hard drive. I then (finally) managed to install a copy of the Snow Leopard OS (the version that the Macbook shipped with) from DVD. I then attempted to bring the machine as up-to-date as possible via each successive OS, aiming to finally reach High Sierra, beyond which the Macbook cannot cope.
I first downloaded Lion and Mountain Lion from the Purchases section of the App Store, but both of these failed, the system claiming checksum errors. Multiple times all had the same result. I then discovered that the final version of each of those two old OSs could be downloaded from the Apple web site, which I did. In both cases, the default installation failed again, also with checksum errors. Doing some research online I discovered that an alternative install file within each image could be used, and in both cases, that worked. So I went from Snow Leopard to Lion, then from Lion to Mountain Lion, relatively painlessly.
Mavericks was next on my list. Downloading from my Purchases in the App Store had the same lack of success as the previous attempts. In this case however I couldn't find a download on the Apple web site, and was loathe to try any third-party offerings, fearing for the security of my system.
Exactly the same with Yosemite, El Capitan, and Sierra. No luck.
Giving up with the plan to install (and back up) each successive version, I had no option but to try going straight to High Sierra. Same problem on trying to download from the App Store, but was relieved to see that this version was downloadable from the Apple web site. I've tried this twice so far today, but on both occasions I got the same checksum error.
Am I stuck forever with a Macbook running Mountain Lion?
Any hints or suggestions would be very welcome.