When using Windows or File Explorer, the font or text size is to small for my taste. I like it slightly bigger and easier to read. It was easy to do in Windows 7 and I found out just as easy in Windows 10 when you know where to look.
So just click on the start button and then Settings wheel. Then click on the Ease of Access section.
The Display option on the left hand menu should automatically be clicked on the right hand side you'll see a slider that goes from a small size A to a larger version. Click on hold down on that slider and drag it to the larger A to make the text larger or to the smaller A to decrease the size.
Keep an eye on the Sample text to get an idea on what size you prefer and then click on Apply just under it.
Make everything bigger.
Then slightly further down you'll find a section that says Make everything bigger, 100% (Recommended), you can click on that and choose another option there instead. Usually 125% and 150% but I think the slider gives you a little bit more control. If you set the text size higher it's automatically going to make some items, like the menu's larger anyway.