You almost never have to do anything with the settings of your screen. However, over time it may be the case that the colors appear slightly different, that the image appears too bright or too dark. You can easily do something about that in Windows.
Calibrating a screen can be done in different ways. First, there is the hardware method, via the display itself. Via the settings of your screen (via the keys on the hardware), you can often change colors, adjust brightness and so on. But that is difficult, if you do not know what the correct setting is exactly.
In addition, you can also buy a device, called a colorimeter, that you hold in front of the screen. However, such a device costs a lot of money (more than 100 euros) and is somewhat exaggerated for the few times you have to calibrate. Fortunately, Windows can do it too.
A colorimeter is an expensive method to calibrate a display.
Before you start calibrating, make sure that your display has been switched on for at least half an hour, and that it has been given the opportunity to 'warm up'. Click Start and type Calibrate and then click Calibrate Display Color when this option appears.
Press Next one and see which image displays the correct Gamma value. When you're up now Next one click, move the slider so that the image resembles the image that displayed the correct Gamma value. Press again Next one and now see which image has the brightness set correctly. When you're up Next one click you can use the slider to adjust the brightness. Do this again so that the result looks like the image you just saw. This way you click through the rest of the Wizard, where you always get examples of the desired result and you have to try to approach it as closely as possible. When you have completed the wizard, your screen is calibrated.
Fortunately, Windows itself can do it too.