upgrading from High Seirra
how to upgrade from High Sierra OS
iMac Line (2012 and Later)
Question marked as
Back up your data, check your applications for compatibility, and depending on which iMac model you have, click on Mojave, Catalina, Big Sur, or Monterey. If you get a Mac App Store preview page, change the https at the beginning of its address to macappstore.
Catalina and newer won't run 32-bit software; download and use Go64 to scan for it. To look up other programs, click here.
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