how I upgrade from El Capitan to Sierra

You are meant to click on the blue links provided in Neils post above.

If you want Sierra follow the instructions below, but any mac that can run macOS Sierra can run macOS High Sierra.

If you do have an operating system on your mac and it is functioning then you can download

Sierra using this method.

How to get old versions of macOS – Apple Support

Go to Download macOS and click on macOS Sierra 10.12

This downloads InstallOS.dmg to your Downloads folder.

The next section can only be done on a mac that is capable of running Sierra,

a mac that came preinstalled with an OS later than Sierra will refuse to do the next bit.

When downloaded open to get InstallOS.pkg, double-click on

that and an installation window will open, read and follow the prompts,

this does not install Sierra but uses the InstallOS.pkg to create the 

Install macOS Sierra.app which you will find in your Applications folder.

(If the installation window asks which disk you want to install to, you must pick 

the disk that you are booted to at the time. Not any internal or external disk that 

you want to eventually install Sierra on, that is for later.)

To start the installation of Sierra double click on the Install macOS Sierra.app.

The copy of the install app self deletes after installing Sierra, so make sure you keep a copy of the InstallOS.dmg

if you need it in future, or you could just make a copy of the Install OS X Sierra.app prior to installing and moving it to

an external drive for safe keeping. 

Hi,

I was very happy to find out that I could still upgrade to an older OS. However, so far my computer is not switching to Sierra.

I downloaded the update and ran it. The installer said that it was successful. I restarted and I am still on El Capitan. Restarted again and ran the installer again in case I'd missed something. This time the installer ran for only a short period of time and said that the installation was successful. Restarted. Still on El Capitan. I created admin user. Downloaded the update again. Again a very quick installation. No change on restarts.

Then I realized that I was not on the final version of El Capitan. Updated to that. Then tried Sierra update again. Same result. Still on El Capitan. I seem to have the update installed already so I'm not sure what I can do next. I don't want to make the jump to High Sierra if I can get Sierra to work. I'm only upgrading because of security certificate changes as of Sept 30 that have made some browsing and downloading difficult.

The installer definitely said Sierra. I downloaded on wifi both times but I'm not installing from the app store so I don't know if that matters. I have a MacBook Pro (13-inch, Mid 2012).

I'd appreciate any more ideas or advice. Thank you!

Leila

Back up your data, check your applications for compatibility, and if your MacBook Pro is a 2010 or newer model, click on Sierra.

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