Writer and Word

I’m teaching LibreOffice at a seniors’ centre which has eight Windows 10 pcs with Microsoft Office installed. I created a Writer document at home to use in class. On seven of the pcs all went as expected but on one, double-clicking the file launches Word, instead of Writer. Also, the file icon on that pc includes the tiny W of Word. We can get around the problem by using Open With but I’d like this pc to perform correctly. Any ideas?
Thank you!

There are many Q&As about setting default programs for Win10 on Superuser: try this one first although if that doesn’t help, there are plenty of others. HTH.

If 7 of the 8 PC are already configured to associate LibreOffice with ODF types (.odt, .ods, .odg …) you should configure the eighth PC in the same way. How to do so is Win stuff. LibreOffice can only do it during installation.
If the .msi is available on the computer you may repeat the install in ‘Change’ mode. Avoid to also associate LibO with MS-Office types on a computer having MSO installed. Otherwise someone else might complain. If you need to wait for a helper to find the installer, you can work around the problem meanwhile by instructing the concerned user to first start LibreOffice and subsequently open the file from its desktop or File-menu.