Win10 update (1809-1909) stalls on tablet

See the tutorials of how to backup your apps. With any luck you could be able to restore them at another computer if you enable Sideloading.

I just spent about an hour looking through the list of tutorials and searching the forum and reading threads asking how to backup apps (including one where you asked the same question but didn't get a useful answer) and all I know is that others have wanted to do this too and that "sideloading" means installing an app from anywhere except the Store.
I'm unclear about enabling sideloading, though - several of the apps I use most are from other sources (including one that came on a disk about 15 years ago) and I didn't have to enable anything to install them.

Maybe I'm not using the right search terms.

OK, thanks. I just checked and Sideload apps was already checked. As I said, I haven't needed to do that before when installing non store apps.

Now how to backup the app from another computer?

I thought you meant to install a Windows Store app to another computer. That's why I mentioned sideloading, so you can install the app from backup rather than from Windows Store. If it is a conventional desktop application, then there are other tools to backup these and restore after a clean Windows installation (or to another computer). I don't remember an example now, but you can Google application backup to see what you can find.

PS: With a quick search I found that: Backup Installed Programs and Applications in Windows 10/8/7 You can probably find many others.

I found a lot of pages like that too. It wants to sell 3rd party software and from the look if it that won't do what I need either.

That looks like it might do what I want but it is outside my skill set.

This looks promising How To Move Windows Store Games From One PC To Another
Except that I can't figure out how to get administrative rights to access the contents of the folder

Right-click on the folder, go to Security, and then give full access (check all boxes) to your account. If you are not allowed to change permissions, you may have to change the folder owner to your account first. I do not remember the exact steps, it's all there.

Sorry I didn't get back sooner. It has been a busy week.

When I right click the WindowsApps folder there is nothing about Security unless I click Properties. In Properties, when I click Security I see "You must have Read permissions to view the properties of the object. Click Advanced to Continue." (next to the Advanced button it says to click it for special permissions or advanced settings).

When I click Advanced the window opens with the Permissions tab selected and it says I need Read permissions again and "Click Continue to attempt the operation with administrator permissions"
When I click Continue a list appears but I have no idea what to do. If I select something from the list The view button becomes available and if I click View a window opens but everything there is greyed out (same for all items in the list).
I am really lost here and don't want to mess something up by pushing the wrong button.

I am just as confused about what I see if I select the Auditing and Effective Access buttons.

At the top of the Advanced window it says
"Name C:\Program FIles\WindowsApps
Owner Trustedinstaller" with a Change button

If I click Change a small window opens that says "Select User or Group" but I have absolutely no idea what to do after that.

I really have any idea about any of this.