Convert Word files to Office files?

I have a new laptop that has converted all of my OpenOffice files to Word files. The problem: Since I don't have Word or it's not activated, it doesn't let me convert the files. The bold font at Office also seems a little different to me. How can I ensure that Word moves into the background and Office takes over command? Have Windows 10.

Is the same file format as good as I know, The files were not converted, but are only opened by another program. Just right-click on the file, then on Properties and at the top with open with just click on change and change.