How to download El Capitan installer from a High Sierra Mac
4309
How can I download an older version of OS X/macOS?
69162
Is installing Mavericks on Hackintosh legal?
31948
Roll back from OS X Mavericks ( or any newer OS) to Mountain Lion
4251
How do I get my Mac to boot from an Ubuntu USB key?
129143
Error upgrading to High Sierra
132604
How do I install OS X Yosemite without a working Mac App Store application?
121136
How to fix "macOS needs to repair your library to run applications" after High Sierra upgrade?
23917
How do I install Ubuntu on Windows, from a Mac?
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Installing OS X not from App Store
46084
Can I downgrade from macOS Sierra to Snow Leopard (OS X 10.6)?
94510
How do I do a clean install of Yosemite?
11780
How can I download the macOS Big Sur installer on a Mac which is already running Big Sur?
21264
Official way to obtain an OS X ISO file
85156
OS X updater claims installation is successful, but new OS is not installed
93193
This copy of the Install OS X El Capitan application can't be verified. It may have been corrupted or tampered with during downloading
42101
How to Install Octave in El Capitan?
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Why can't I find OS X Yosemite in the Mac App store?