Pre-Installed Office 2016 "Fighting With" Post-Installed Office 2010

With my continuing efforts to assist my brother in tailoring his new ThinkPad (X1 Yoga) laptop, I've recently discovered an unexpected problem relating to Microsoft Office, and specifically (at this point), with Word. As indicated in this post's title, his laptop came with Office 2016¹ pre-installed. Subsequently, Office 2010² was installed by his I/T staff to eliminate the extra expense of leasing (via Office 365) or purchasing/activating the resident Office 2016 code. But Windows seems determined to make using Office 2010 unnecessarily difficult.

Specifically, regarding Word 2010, with .docx associated with this 2010 version, whenever one clicks on a .docx document, Windows pops up a message stating something like — this is a rough paraphrase; I can't recall the exact wording — "This application cannot run on your PC. Please go to the Microsoft store to find an application that will work with this file." However, .docx files open easily from within Word 2010.

Being curious, I'm all for understanding the how's, why's and wherefor's of this seeming impediment, but I don't want to unduly burden any readers/respondents with an explanation. I'd be happy just to learn how to correct this situation; i.e., to be able to click on a .docx file and have it open within Word 2010.

Perhaps it's necessary to uninstall Office 2016. It might be preferable to find another solution, in the event my brother may (at some point) want to go ahead and start using Office 2016. Is there a way to accomplish this without doing a total Office 2016 uninstall?

I appreciate whatever ideas you could send my way.

Thanks,
—Thri
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¹ From looking at my brother's system, it appears that Outlook is no longer (necessarily) included in the Office suite of products. Is that correct? Perhaps, same with OneNote? I recently downloaded (for free) OneNote 2016 onto my brother's computer.
² Upon searching for the executables (.exe files), I found them within a Microsoft Office 2014 folder! Hmm… kind of wonder why it's not called Microsoft Office 2010.

Is the Office 2010 32 bit, like most PCs at that time ? Office 2016 and Office 2010 can run side-by-side only if the bit versions match; ie, both 32 or 64 bit.

Also, if you open a 2010 Word in 2016 Word, there should be a 'compatibility mode' in the document title bar to preserve the layout.

Since it was his I/T staff that installed Office 2010, it should be their responsibility to address the issues in whatever 2010 version they installed.

On the Office 2016 (?) (Office 365 (?)) that’s preinstalled on his new ThinkPad (X1 Yoga) laptop the I/T staff should address that also with whatever status it’s in: trial version, activated version?

On the application that it cannot run on your PC, that doesn’t make sense.
I have installed Microsoft Office 2000 on one of my Win10 computers and Microsoft Office 2007 on my sons Win10 computer and the training computer where I volunteer also has Microsoft Office 2010.

Although the versions are different, my brother has a Win 8.1 upgraded to Win10 that came with Office 365 pre-installed and I think it had a 30-day free trial with it but he purchased Microsoft - Office Home and Student 2013. I installed it and it runs excellently without any problems. I did not have to uninstall Office 365 and I do not think you should have to either: all I did was go into settings and set up notifications not to recommend Office 365 or whatever it said. With that said though, if the Office suite on your brother's computer has been activated, I think MrGeek ideas look good.

Compare Microsoft Office versions for Outlook and OneNote etc.
https://www.microsoftstore.com/store...mpare_22092015