Chosen Solution
I Found An Old Mac Pro Without An Hard Drive. I Was Able To Put In A WD Hard Drive But I Have Not Found A Way To Load The OS.
Owen, first find out what year your machine is. The reason is the The 2009 model will not upgrade to High Sierra without an EFI flash. Also the 2006-2008 model look very similar to the later machines but will only take up to a maximum of El Capitan. Go here and input your serial number then let us know what you have. https://everymac.com/ultimate-mac-lookup…
I’m not too sure on macs as a whole, and which OS’s are compatible with which devices. I’m a PC guy because I like the flexibility they give me. but, if logic follows, even if you cant use High Sierra on this device, it should work the same regardless of the OS you decide to install. http://osxdaily.com/2017/10/02/clean-ins…
