how to upgrade to macOS High Sierra 10.13

Yes that is correct there is no High Sierra 10.13, Apple replaces each full installer with the next version, so when High Sierra was updated to 10.13.1 then 10.13 was retired and not available for download. The pattern follows with 10.13.2, 10.13.3 etc etc etc.

High Sierra is still available for download, here, How to upgrade to macOS High Sierra - Apple Support

this will down load the full installer, 5.23GBs and will install the latest/ last version 10.13.6.

there is no need for you or anyone else to search for 10.13.

You may have been in the position where you were trying to install updates to High Sierra, these updates require you to be already running an earlier version of High Sierra before they can be installed, thus you get the error message, which says you need 10.13. The error message is very badly worded and therefore causes this confusion.

OK, that one is "late" enough: HighSierra and later can run on that one.

stop and delete the downloaded HighSierra first. Empty the Trash can.

Restart.

Then download High Sierra from here:

https://support.apple.com/en-us/HT208969

(use this link when your mac can handle more than HS).

Jay,

Naw, it's just that you have an old copy already in Applications, there are 2 cures...

Disconnect from the Internet & set the Date back to 2014, then you can run the Install MacsOS High Sierra App in Applications.

Or... trash the App in Applications then a new copy can be downloaded.

https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=12

Naw, it's just that you have an old copy already in Applications, there are 2 cures...

Disconnect from the Internet & set the Date back to 2014, then you can run the Install MacsOS High Sierra App in Applications.

Or... trash the App in Applications then a new copy can be downloaded.

You can certainly upgrade from Sierra 10.12.6 to High Sierra, look at this screenshot from the Apple Support page,

How to upgrade to macOS High Sierra - Apple Support

So have you looked and followed the instructions on Section 4 to Get macOS High Sierra, this will allow you to download the full installer which should be about 5.25GBs. Some people report that they only get what is called a stub installer about 19-22MBs, if you get that then double click on it and it should start to download the full installer. Please use a cabled connection to your router as this should provide a more stable connection.

Prior to that make sure there are no disk error reports in Disk Utility> First Aid. Yes again.

Can you share screenshots of what you are seeing and any error messages.

If you see Open in the App Store it usually means you have a partial download of High sierra, look in your Applications folder

for Install macOS High Sierra.app, if you see it move it to the Trash and empty the Trash. If you were using Wifi before now try a cabled connection to your router. Restart your mac and go back to the App Store and try downloading High Sierra again.

If the App Store is showing Open, then it is detecting a copy of High Sierra on your Mac. Go to your Applications folder and look for Install macOS High Sierra.app, move it to the Trash, empty the Trash. Connect your Mac to your router using a cable rather than WiFi. Restart your Mac go back to the High Sierra App Store page and now click on Get, do not use the Mac while it is downloading.

This post is now 5 pages long I bet if you read through it you would have found this information.

And why not start your own post instead of leaching on a very old and long post.

Same frustration -- using Firefox 74. Its redirection thru iTunes goes nowhere.

Then the light came on...

I switched over to Safari (v12.1.2) and everything works out okay. Went to the High Sierra download page.

Well, three times out of four anyway. The third try went to Catalina instead. Go figure...

Until/unless Firefox gets fixed (soon, I hope, since I find Safari clumsy and chummy most of the time) I'll be working Apple upgrades through Safari instead of Firefox. Your insistence turned on the light.

Thanks, BDAqua.

Hey Chrysie! I have iMac 2009 and after 4 frustrating days, I installed high Sierra successfully. I’ve been using my Mac 2009 for two days and everything works great even my old adobe creative suit CS3. Here are the steps: step 1. google Mac OS high Sierra download link. Only pick the link from apple. If it’s stuck at 3/4 way and says something like ....can’t download high Sierra because damaged... it means you have an incomplete download HS before. Go to system preference > Applications and delete the high Sierra OS. Empty trash. Restart. Back to step 1. After you have downloaded HS software. Problem n2 during activation, it will not let you install on Mac main HD .... you may not install on this location because legacy FileVault is attached with some users...means the latest FileVault version is conflicting with the old version. I deleted my main user since 2009, this one is attached to old FileVault, but before doing that, I created two new admin users just in case. Restart and reactivate HS again and follow on screen instructions and that’s it. On your first admin user sign in. Leave the computer alone for an hour, let it boot up all the programs and it will run smoothly. I was impatient and started using right after five minutes and it was like driving through the rush hour. Safari, wifi and others were really broken. So I restarted and let it be for the evening.

Naw, it's just that you have an old copy already in Applications, there are 2 cures...

Disconnect from the Internet & set the Date back to 2014, then you can run the Install MacsOS High Sierra App in Applications, so expired Certificates are not expired.

Or... trash the Install MacsOS High Sierra.app in Applications then a new copy can be downloaded.

Back up your data, check your applications for compatibility, and download High Sierra from the Mac App Store.

(173828)

Ah, you've downloaded the 10.13.6 Combo update I think, delete it & try this...

https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=12

Don't use Firefox...

https://itunes.apple.com/app/macos-high-sierra/id1246284741?mt=12

I fixed it and downloaded High Sierra on iMac 27 inch late 2009 . Here's how to do it: Go to Application > delete the broken link Mac OS high Sierra folder > reboot and download it again. Problem one is fixed.

Here is problem N.2 along the way. You will see the message: "you may not install to this volume because it has legacy filevault users." The new version of filevault conflicts with the older version. I created 2 new admin users just in case then deleted my first user ( been there since 2009) reboot et voila! follow the instructions.

Because you had downloaded before either wrong version or incomplete download, it's "Damaged." Remove the damage High Sierra OS in Applications > reboot > download again from Apple site only. Here is the download link https://support.apple.com/en-ca/HT208202. Cnet or Softonic installed virus on my Mac before. Stay away from them.