Temporary Word documents

They aren't really stored anywhere. They're temporary working files. Word makes one every time you open a document. It will remain there until you close the document you're working on.

You also shouldn't be seeing them as they're hidden files. Not unless you changed your Mac's settings to show hidden items.

Where does Mac or Word hide them?

It's not really hiding as much as you're just not supposed to see them.

I pressed Command+Shift+. (period) to show hidden items. Word will always create the temporary file in the same folder the file you opened is in.

In my folder of Word docs:

On the desktop:

When I closed each document, Word automatically deletes the temporary file.

What am I supposed to do when my document name is changed to the ~ file name?

You're not supposed to do anything with them. You'll only succeed in screwing up Word's tracking of its background files.

Can I tell Word to not create these interim files?

No. It's part of how the app has been written to function. Leave them alone. Word will take care of its own working data. Better yet, click anywhere on the desktop (so Finder is the foreground app name at the top left), and press Command+Shift+. so you stop seeing hidden items in the first place.

Ah! Okay, that's very different and unusual.

From what I can gather, Word is automatically trying to save files to a folder it shouldn't. On top of that, it's giving them a name with a period at the beginning. Which in Unix means the file/folder is hidden from the user.

But, as the user, you also aren't supposed to try and save anything there. Which it tells you by declining due to lack of permissions. It's a hidden folder only the system has read/write access to.

See if this helps. Open Word. Close any documents it may open, including a new blank one if it does that. Open Word's preferences and click on the File Locations icon. Click the Reset button. Close Word. Launch Word again and try to save any new document. What does it do now?

Running Catalina on only 4 GB of RAM is iffy. But that mostly just means it will run slowly as the OS will spend a lot of time swapping between RAM and using disk space as virtual RAM.

Is it just this one file that keeps trying to rename itself? If so, another quick thing to try would be to open that file. Start a new, blank document. Copy/paste the content from .~WRD000 into the blank document. Close the misbehaving doc and save the new one. Hopefully, that one will allow you to save it normally.

To note, I'm suggesting quick, simple stuff first. This is how I approach almost all computer snafus. Easy first. If that doesn't work, dig a little deeper. If not that, get out the backhoe.

A responder suggested not using my external drive for my backup.

Not sure why they'd say that. Any backup on the same physical drive as the original isn't any kind of backup. If the drive dies, everything is lost at the same time.

I think Time Machine backs up or places temporary files into the same folder location as the original Word file.

I never use TM, but I can tell you that you should never manually save to, or delete any data of a drive/partition being used by it. Only TM should ever touch the contents.

Not that you can't have the external do double duty, as long as you create a hard partition on it so one section is dedicated to TM, and the other partition to whatever you want to put there.

I was having some issues with an external drive requiring my Apple account password to modify the files/folders.

A very common nuisance of the way Unix sets drive defaults. Highlight the partition/drive you want full access to (NOT the TM drive/partition). Press Command+I, or choose Get Info from the top menu bar. Either is the same thing. Expand Sharing & Permissions if necessary. At the bottom right, click the lock and enter your admin password. Turn on the check box to Ignore ownership on this volume. Close the Get Info box.

Now you can write whatever you want to that drive/partition.