There are several ways to adjust the size of text and items on your screen. I'll discuss the commonly used wrong way and the right way.
I know how you feel. My eyes aren’t all that they used to be either.
The good news is that it’s actually easy to make the fonts bigger, but the setting is hidden well.
The bad news is that it’s also easy to do the wrong thing and end up with something that seems better, but often isn’t.
The wrong thing
Changing the screen resolution is the wrong thing to do.
In the past, there was an approach that worked fairly well on CRT-style monitors. With the rise of the LCD screen, running at anything other than the screen’s native resolution can have unintended consequences.
For example, let’s say that your display is capable of handling a resolution of 1920×1200. That’s its native resolution and the resolution at which it works best.
To make things appear larger, you then change the resolution that Windows uses to 1280×1024. Either of two things will happen:
- The 1280×1024 image will be stretched by the monitor to fill the 1920×1200 pixels that make up the display. You’ll note that that’s not an even multiple, so the display now has to “stretch” each pixel that Windows gives it across 1.5 pixels horizontally and 1.17 pixels vertically. Because there’s no such thing as a fractional pixel, the monitor just has to try its best – often resulting in images that are indeed “bigger,” but also significantly fuzzier.
- The 1280×1024 image won’t be larger at all; instead, it will be centered by the monitor using 1280×1024 physical pixels on the screen and surrounded by a black border of unused pixels.
Neither effect is great and it often makes this worse instead of better.
Fortunately, there is a different approach.
The right thing: DPI
In Windows 7, right-click on your desktop and click Screen Resolution. No, we’re not going to change the resolution after all, but the link for the setting that we do want is there:
Click Make text and other items larger or smaller.
As you can see, this setting will increase the size of everything, including text.
For comparison, I’ve superimposed the screen at 150% on to the normal 100%:
You can see that images, such as the desktop, are unaffected, but all of the text and icons as well as the task bar and windows controls are now 150% bigger than they were before.
Note that when you make this setting change, you may need to logout and then log back into Windows so that it can apply it.
If the options of 100%, 125%, and 150% aren’t enough, you can manually adjust the underlying setting.
DPI, or dots per inch, is what the setting above controls. The default is typically 96 dots (or pixels) per inch, but you can adjust it to almost anything.
Once again, right-click on the desktop and click Screen Resolution, and then click Make text and other items larger or smaller.
In the resulting dialog, click the Set custom text size (DPI) link.
You can select a custom percentage by using the drop-down or typing in your own percentage value.
You can also click the ruler; hold and drag it to the right and left to make changes as well.
In either case, the text will be redrawn to show the effect of the proposed change.
Windows XP has the same concept for DPI settings, just in a different place.
Right-click your desktop and click Properties. Select the Settings tab. Click Advanced and then select the General tab.
The DPI drop-down in XP has two settings, Normal and Large, but it also has a “Custom setting…” option:
As you can see, it’s the same custom dialog that’s still used in Windows 7.
This concept of using a “dots per inch” setting to scale what’s written to the screen has been a component of Windows for a long time. Applications aren’t supposed to ignore that and most do not. Most play by the rules.
Unfortunately, you may encounter an application where the DPI setting has no effect. Occasionally, you may even encounter worse – applications that use the setting inconsistently so that changing it making a mess of that application’s UI.
Blame the application; it’s not playing by the rules.
And finally, if you make things too big, you may get a warning from Windows that the setting may result in some things not being accessible. A great example is if things are zoomed in so large that a dialog box is too big to fit on the resulting screen and its OK and Cancel buttons aren’t visible. That’s something that you’ll simply need to compensate for one way or another – either by going back and reducing the DPI setting or by determining if there’s another way to accomplish whatever it is that you’re attempting to do without having things appear off-screen.
Update: CTRL+ and CTRL-
Many, many people have been commenting that they use the CTRL key and + or – to make text larger or smaller, respectively, or use CTRL plus the mouse wheel.
This is a very effective approach, when it works.
CTRL+ and CTRL- are application specific, they are not a part of Windows. Now, it just so happens that they’ve been implemented fairly consistently across most web browsers and many email programs.
But they will not affect the size of text in, say, Windows itself, or many if not most of the other applications that you might run on your system.
The techniques outlined in the article above are about making the text – all of the text regardless of what program you are running – larger (or smaller).
That being said, CTRL+ and CTRL-, and CTRL+wheel are very convenient if all you care about is the web page or email that you’re viewing.
(Update added 10-Sep-2013.)