how to upgrade to macOS High Sierra 10.13

Apple is probably turned off the server of this version and not telling anyone. Adobe did that to older version of PS Creative Suite but they tell you on the net so you don't have to waste your time to figure out why it's not downloadable anymore. Apple should be more upfront.

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.

I'm haven't tried downloading the High Sierra but need to upgrade software because i have the Sierra 10.12. Is the High Sierra the latest compatible software for iMac late 2009?? I'm hesitant to download High Sierra but need to upgrade.

Indeed, Eau Rouge is right ! Mark his post as solved and be happy, HighSierra is OK.

A new mac now means Catalina which is still not very good and has a lot of problems for older software and cannot be downgraded. To avoid that I bought an unused mac with HighSierra on it from an old stock to be sure of continuity when one of my older macs should go broke...

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.

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.

When I try to open the High Sierra install from the App Store I get the message "This copy of the install macOS High Sierra application is damaged, and can't be used to install macOS." Any idea on how to work through that?

When I go to the App Store to download High Sierra 10.13, I get this message: This copy of the Install macOS High Sierra application is damaged, and can‘t be used to install macOS. What do I need to do?

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.

I've done it but you should add another RAM 4GB it will run really fast. Don't buy from eBay. Search local reseller for G.Skill brand. 4GB, $20. If you don't need it, don't upgrade. Old Sierra was the best OSx for my iMac.

I am trying to upgrade to High Sierra as well. Every time I go to the Apple Support page, instead of saying download, it says open and when I click on it a message comes up that says the installer is damaged and can't be used.

Hi Michele,

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

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.

There is a thing called Google if you just make an effort to type in few words instead of whining. I had replied few times to many people with the same subject. You google for Mac OS high Sierra download link. There are lots of links but only use the Apple link. Avoid cnet, softonic, and other free sites or you can get viruses. When it done buy another 4BG ram add on and your Mac will run faster than before. My imac 2009 has been running Photoshop and Corel Painter for two weeks flawlessly since I upgraded to OS high Sierra. 4GB G.Skill ram is $20. Stay away from eBay Ram. Good luck!

I have an iMac (21.5-inch, late 2009) running macOS Sierra. I want to upgrade to high sierra. I downloaded it and began installation. But when it tried to restart, I received the following error, “An error occurred while preparing the installation. Try running this application again.” I tried several times, including letting the installer restart and restarting myself. All applications appeared to have close. Any thoughts?