why can't i update my mac

amsiortega Said:

"why can't i update my Mac: I can't get to an option to update my system software for my Mac. I want to install Excell and can't do it unless my software is updated."

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Go Here: How to Update the Software on your Mac?

IMPORTANT: Prior to and after updating your Mac, create a Time Machine backup of it. That way you have something to restore your Mac from, should anything go wrong with the update

Update will apply all the recent modifications to the SAME major version.

To install a newer major version, you need to UPGRADE, much more like buying a new version of MacOS, on sale for $0.

I suggest you stop short of Big Sur for now, as it has MANY incompatibilities which may be a shock

How to get old versions of macOS - Apple Support

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