LibreOffice on shared computer

LibreOffice is set as the default reader on my laptop, and all of my files are in the cloud, with no problems.
I also use a shared desktop pc where I can readily access those files, but MS Office is set as the default on it and I really would prefer my files (about 500 documents plus a few spreadsheets and presentations) to open in LibreOffice while still allowing the other person to use Office.
Is there any way of achieving this? Nothing has come up in my searches.

Have you tried opening the application first (Writer, Calc,whatever) and then using it to navigate to your files, rather than opening the file or document directly? After opening a file the first time this way, it should appear in the recent documents list of the application and you won’t have to search for it again. I don’t have Windows 8 to test it but this method should work regardless.

Yes I am aware of that method, thank you, and I can confirm that it does work on Win 8, but I am hoping for a way of (A) getting any existing document on “my half” of the shared computer to open automatically in LibreOffice when I click on it, rather than me manually opening LibreOffice first and then using it to browse for the file I want to read, and (B) doing it so that the other user can still open theirs in MS Office.
I have achieved this on my laptop, of which I am the sole user, simply by setting LibreOffice as the default, but I dare not do that on the shared pc for fear of a divorce.

I understand. However, in my experience it is always safer to Save and Close (2 operations) a document before closing an application (a third operation). This avoids any inadvertent loss or corruption of a document from having left it “open” in the application, no matter how inconvenient it might seem. Maybe you have just been lucky so far :-).

Just got to this thread by accident, and neither found “associate” nor “extension” in it. Therefor:
If the users of the shared computer are known to Win under only one user ID, the obvious way I can see is that they always save their office-files to the native “formats” of their preferred office suite, and associate the repective extensions with the program as required.
An automated process of changing the associations when starting one of these suites would reqire dangerous tampering with the registry. Fortunately we don’t know how, anyway.
In fear of divorce I wouldn’t share a user ID.
Aha! Just finally read the UPDATE below, and found the questioner actually did it this way.
(Volatile marriages may be a topic in a different forum.)

This looks like a Windows problem rather than an LO one. Does the advice at https://www.computerworld.com/article/3046707/microsoft-windows/windows-10-quick-tips-how-to-share-a-single-pc.html help?

Thanks for the link, that describes precisely how my Win 8.1 pc is set up, with husband and strife users.
I has become clear to me from my trials that it is the computer that decides what the files open in (thanks to MS for their dominance) and not anything else. In my innocence I earlier thought that if my files were changed to .odf in the cloud, they would open in LibreOffice on the shared pc, but that is not the case.

UPDATE, MARCH 2021. SOLVED!
I reinstalled LibreOffice on the shared pc I use.
Choosing a random text document, I right-clicked on the file and selected Open With, where I chose LibreOffice. That did precisely what I wanted, the doc opened in Writer, though it looked as if it was going to mean a number of extra clicks for every one I wanted to look at.
But after closing that document I right-clicked on another one, when this time it said, How do you want to open this file? Do you want to continue using this application.
When I closed this one, I observed that all of the text documents in my file explorer now had the LibreOffice icon. Fearing that all of the other user’s docs would have been changed as well, I logged onto their “half” where I was greatly relieved to find that the documents there still showed the Word icon and they opened in MS Word.
So I am happily using LibreOffice on the shared pc and my marriage is secure (for now).

You’re welcome. And thanks for your response. It is nice to know our suggestions have helped, even when they are not quite what we would like to hear.