I am doing a clean install of Mojave on my MacBook - it has simply not been possible to upgrade from High Sierra to Mojave automatically. I understand that it will overwrite all of the HDD contents I know I can simply copy document files etc and then copy them back into the new system But, will a Time Machine backup from the original High Sierra be able to reinstall all of my programs?
Thanks for the help. The problem turned out to be both more complicated and simpler than I originally thought.
I had installed a Tar Disk in 2015 and more research showed that quite a few users were having the same problems and error messages as I was.
I followed the instructions here - https://www.tardisk.com/pages/uninstall-sierra - to uninstall the Tar Disk - NOT removing it because I was coming from High Sierra, as the instructions said. It DID NOT solve the problem.
I then went through the whole rigamarole again; shut down my MacBook and physically removed the Tar Disk. I then reopened the Disk Utility and reformatted the internal Mac SSD - installed Mojave from a USB and it seems to have worked.
To answer my PRECISE question - now that Mojave is installed - Time Machine has been able to recover/reinstall all of my files and programs
Thanks again to those of you who responded
Though your proposed solution may not actually get to the root of this issue, assuming you can successfully install a fresh Mojave OS onto your machine...
Yes, a Time Machine backup can be used to Migrate to a newer macOS. The only difficulty would be if you try to Migrate to an older one.
Perform the Migration immediately at first signup/login to the new OS. If you do it later, you will end up with two accounts rather than one simple migration.
Theoretically, you should end up with essentially the same as if you had just done the update the regular way, all apps, prefs, docs exactly as you had them.
If your nervous about depending on Time Machine backups you should consider that Carbon Copy Cloner might be your best simple solution.
It will let you go into the weeds and grab the files that are relevant when transitioning OS versions and disk formats (HFS+ vs APFS).
Time Machine is great for those weekly backups in case your disk suddenly dies, but CCC is the advanced route that gives you the flexibility and options you might need (I just did a Mojave back to High Sierra restore combined with APFS back to HFS+ with CCC).
https://bombich.com/kb/ccc5/everything-you-need-know-about-carbon-copy-cloner-and-apfs https://thesweetsetup.com/apps/best-app-for-bootable-backups/ https://www.maketecheasier.com/create-bootable-clone-of-mac/
Just make sure that your not running into any problems because of going between a case-sensitive & case-insensitive disk format.. but https://github.com/cr/MacCaseSensitiveConversion will help with that :)