You can easily enlarge the text on your screen by switching to a smaller resolution...but I don’t recommend it. You’ll lose all of the advantages of high-definition (and likely get a soft-focus visual effect), and you won’t be able to put as many windows on your screen.
You’d be better off changing the settings in Windows that control the size of your text and other objects, such as icons and the taskbar. Here are instructions for Windows 7, 8, and 10.

Windows 7 & 8

Open Control Panel’s Displaytool. Here you’ll find three size options: Smaller (the default you probably already have), Medium (which increases the size by 25 percent) and Larger(increases it by 50 percent).
Want more options? In Windows 7, click Set custom text size (DPI) in the Display tool’s left pane.
In Windows 8, click Custom sizing options below the Larger option.
Either way, you’ll get to the Custom DPI Setting dialog box. Here you can select another size by dragging the the ruler image horizontally. (By the way, DPI stands for “dots per inch.”)
The size of your text won’t change when you close the dialog box. But you will have a new option in the Display tool.

Windows 10

Click the Start button and select Settings > System. You won’t have to go to the Display tab; it’s the default. You’ll see a slider bar for changing the size of your text and “other items.”
That slider bar looks like a big improvement over the limited three options of the earlier version. But try using it, and you’ll quickly discover that all it offers are the same three options: 100, 125, and 150 percent.

If you want another size, click Advanced display settings near the bottom of the window, then scroll down the Advanced Display Settings window and select Advanced sizing of text and other items.
This brings you to Control Panel’s Display tool. You can click set a custom scaling levelto get the Custom DPI Setting dialog box discussed above—although Windows 10 recommends against it (I didn’t encounter any problems).
For additional fine-tuning, use the “Change only the text size” tool. It allows you to change font sizes in particular contexts, such as the Title bars or Tooltips.