New Mac setup, but all my Word files are now .odt

The files haven't changed. What's changed is the default handler for those files.

Right click on one of them. Click Open With > Other.

Select the app you want to use and check the box for "Always Open With".

To clarify a bit what I believe KiltedTim meant: you can change the default application associated with those files in the Info window.

select one of these files, press Command-I to open the Info window.

Locate the Open With and change that to Word. Then click "Change All" to apply it to all similar files.

And you told us initially they were all with an .odt extension, then some have their extension hidden, and now you state they are Word documents but with NeoOffice apparently being set as the default opening application. Not the least bit confusing…

Select any one of documents with the NeoOffice icon on it and press option+cmd+i to open a Show Info panel. On its Open With section, select Microsoft Word, and then Change All… and follow through with that panel. Now, the default opening application will be MS Word, and if you want the file extension showing, you can do that through the Show Info panel too.

Luis,

The internal document structure of .odt files is entirely different than Microsoft Word documents and although MS Word can open them does not mean there is a corresponding feature or appearance in Word. Although LibreOffice and OpenOffice intent is to be Word clones, that does not always mean 100% document interchange.

Once these documents are renamed, their origin is obscurred and any attempt to later open these documents with an application that does not understand .odt will fail — to the consternation of the user who may have forgotten these were not originally .docx.

I would leave them as .odt, open in Word and save as .docx as appropriate.

I can't imagine how something like that would happen.

You can rename them all rather quickly, though.

In the Finder, press Command-F to initiate a search, and set "File extension" to .odt

Then select them all; control-click, choose Rename...

then Replace text and enter Find: .odt and Replace with: .docx

Did you try rebuilding the icon cache?

The .odt file extension is associated with an OpenDocument text document, created by LibreOffice Writer, OpenOffice Writer, or another word processor. You can open an ODT file with Microsoft Word, LibreOffice Writer, or Google Docs. Those programs can convert ODT files to DOCX, DOC, PDF, and other document formats.

https://fileinfo.com/extension/odt

User wrote " Have setup a new Ventura M1 Macbook via a Time Machine backup of my old Macbook. "

Are you 100% positive the files that were used from the TM Backup were in fact .docx files ?

If so, the suggestion to rename all the files back to .docx seems reasonable and painless

VikingOSX

Of course, the structure of odt or docx are completely different.

I was never suggesting that renaming would change that.

But the OP was adamant that the file extension had changed (I can't fathom how that could have happened, but still). I just pointed out an easy way to rename multiple files.

FWIW, the .odt extension indicates the files were created by apps such as LibreOffice, OpenOffice, etc. I don't know why the extension would have changed from .docx.