I have a mid 2009 MacBook Pro still on its original software cant upgrade
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
158145
A software update is required to use this startup disk - does not update
121136
How to fix "macOS needs to repair your library to run applications" after High Sierra upgrade?
60077
Fresh install Mac OS Sierra and MacTeX
150010
Installing Mavericks on a brand new machine that shipped with Yosemite pre-installed?
11780
How can I download the macOS Big Sur installer on a Mac which is already running Big Sur?
86088
What version do I download for my Mac?
84324
With a firmware password set on a Retina MacBook Pro, what are recovery options?
68614
Is it possible to install an old version of Mac OS on a new Mac?
3612
Can I downgrade to Mavericks after installing Yosemite (beta/developer preview)?
126915
Upgrading an old mac mini intel 1.1 for Lion
93399
Reinstall MacOS Sierra
12614
Upgrade problem
67481
How to revert a do-release-upgrade?
151392
Upgrade to higher memory or faster processor on MacBook Air
43778
Is it possible to "upgrade" from a 32bit to a 64bit installation?
27419
User update needed after updating to Mac OS X Yosemite