Actions taken:
- Since the nVidia driver contains profiles for all Office programs, i started there, changing various setups. No solution.
- Then i set the registry back to it's orginal state regarding fonts for menu's, icon etc... (just used the backups i made when changing them). Same thing can be done through a tweaker but i do this directly through the registry. No solution.
- Then checked these changes where put back to orginal by running a tweaker and see what was set as default. All good, Windows 10 is back in it's original state. No solution.
- Then played around with 3 different video driver versions. Went back to over 1,5 years old. No solution.
- Then removed the last one i installed as test and used the one that comes standard with Windows 10. No solution.
- Then i installed Office 2010 with some result. There's clearly a difference between Word 2010 and Word 2016. Just check the spacing:


Both have some weird spacing between the letters, sometimes it's big, sometimes it's small or non existant but both programs differ in output.
Also check the a's on Verdana 9 in Word 2010. Sometimes there's more space between the letters a, sometimes not, like on the last 3 a's. The same thing happens in OpenOffice.
One thing where it does not occur is in any text in a cell in Excel. There the spacing is all equal...? In both versions, 2010 and 2016.

Now, i'm 100%, no make that 200% that in my previous setup, Win 10 upgraded from Win 8.1 this did not exist (nor did it in Win 7 and before).

I also did another check between both office versions:
The standard font for both is Calibri 11.
This font behaves a lot better but if you look closely...
Result:


The 2010 version definatly looks better then the 2016 version. The Calibri font show minor problems compared to the Verdana font.
The standard Calibri 11 font has no problems (or at least so minor that there not really visible or catch the eye). The Verdana 11 on the 2016 Word isn't bad either.

Still, since it can't be a driver issue anymore (at least not an nVidia one since all traces of that one have gone), it could only be some Windows 10 thing... but what?

Edit: Fonts like Segou UI are just perfect (or the differences are so small there not noticable). But that's a font that i don't want.
I never understood why Mircosoft are pushing their own fonts without the (direct) ability to change them. It started of with IE8 and spreads more and more.