Wrong Office version set as default

I'm moving from Office 2007 to Office 365 but I don't want to uninstall 2007 until I'm confident in my use of 365. (And maybe upgrade my PC. It seems to me that performance has slowed with 365.) The problem is that my file association only says "Microsoft Word". It doesn't specify the version-and 2007 starts when I open it from a file. How do I change the file association so it opens Word 365? (Have the same problem with Excel but frankly, if you can tell me how to change one I'm pretty confident I can figure out how to change the other.) Thanks.

No answers? I'd think this would be a fairly common problem.

Have you tried Start>Settings>Apps>Choose default applications? If that only offers one (wrong or unknown) version of Word, find a docx file in explorer, rt-click and select 'open with...', then select 'more apps', and if Word 365 is not in the list, try 'look for another app' at the bottom of the list: go find Word365, wherever it may be found (I don't have it).