macOS 10.13 Sierra

It sound like you are trying to download a update to High Sierra. Updates to High Sierra are not Full Version of High Sierra. To achieve this follow instructions below and it should download the Full Installer of High Sierra 10.13.6. Once installed, it will present addition update and Security updates. The last Security update for High Sierra was in November 2020.

The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

With the above information in-hand - follow this How to get old versions of macOS and verify what version this computer Qualifies to install. Make sure to use Only Safari to commence the download as Others may not work

Make a Time Machine Backup Before attempting. Notation - Mojave is the Last version to support 32 bit applications / extensions and Drivers. Catalina and Big Sur Only support 64 bit and there is no workaround.

Are there any AntiVirus, Disk Cleaner, Optimizers, Defrag, VPNs etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation.

The instructions are correct.

You have been trying to install updates to macOS High Sierra, these require you to be already running

an earlier version of macOS High Sierra.

To upgrade to macOS High Sierra you need the Install macOS High Sierra.app

as described above.

When Apple introduces a new OS the first version as in the case of High Sierra will be macOS High Sierra 10.13.

When an update arrives the previous full version gets removed from the App Store and is replaced with 10.13.1.

The same was true when version 10.13.2 was released, 10.13.1 was removed from the App Store, this

continued to the last release which was 10.13.6, which is the version you see in the App Store now.

There is no full versions installers for 10.13, 10.13.1, 10.13.2,10.13.3, 10.13.4 or 10.13.5.

The Apple Support Downloads page contains the Delta and Combo updates for macOS High Sierra

but as stated earlier they are updates and can only be applied if you are running an earlier version

of macOS High Sierra.

You can only install a full working version of macOS High Sierra by downloading the Install macOS High Sierra.app

from the App Store.

As you can see the full installer app as pictured above is 5.23GBs.

The updates you erroneously tried to install would have been between 1 to 1.5GBs in size.

As you have been given the correct instructions about three times now you should

now get on with downloading and installing macOS High Sierra.

High Sierra 10.13 Does Not Exist any longer and is not offered by Apple Any Longer. The ONLY VERSION available is High Sierra 10.13.6.

What Browser is being used as Only Safari will work. If using any other Browser like Chrome, Firefox - it will not work.

What is the Exact Age of this computer as outlined in earlier posting About this Mac will determine the Age of the Computer and even IF IT QUALIFIES to Install High Sierra

If is does appear on the BELOW LIST - It DOES NOT QUALIFY

macOS High Sierra - Technical Specifications

General Requirements

• OS X 10.8 or later
• 2GB of memory
• 14.3GB of available storage to perform upgrade*
• Some features require an Apple ID; terms apply.
• Some features require a compatible Internet service provider; fees may apply.

Mac Hardware Requirements

For details about your Mac model, click the Apple icon at the top left of your screen, choose About This Mac. These Mac models are compatible with macOS High Sierra:

• MacBook (Late 2009 or newer)
• MacBook Pro (Mid 2010 or newer)
• MacBook Air (Late 2010 or newer)
• Mac mini (Mid 2010 or newer)
• iMac (Late 2009 or newer)
• Mac Pro (Mid 2010 or newer)

Then follow the instructions by PPhilips above, click on the link

How To Get Older Versions of macOS

Go to the Download section and click on macOS High Sierra.

This will redirect you to the App Store High Sierra download page.

From there you can download the full installer app which should

be about 5.23GBs in size and download to your Applications folder.

This is all you need to install a full running installation of macOS High Sierra.

The version is the last version available and is 10.13.6.

You do not need 10.13 it no longer exists so stop banging your head against a wall about that.