Your PC has a built-in "screen capture" function. If you know which keys to press, you can take a snapshot of your entire screen or an active window. After it's captured, you are can paste the screenshot into any variety of image-editing programs and other programs such as Microsoft Word. A saved screenshot can help you show operating glitches to a technician, promote a computer product online or just brag about a video game's high score. No matter your reasons for capturing the screen, the process takes just seconds.
Click on the window you want to capture. You can capture your entire screen or deliberately select one specific window.
Press and hold the "Alt" key if you want to capture just the active window. If you want to capture everything, don't press "Alt."
Press the "PrntScr" key on your keyboard (it also may be the "PrtScr/SysReq" button or similar). Your screen is now captured to the PC's clipboard. You can only capture one screen shot at a time, so don't capture the screen again until you paste the screen image into a program.
Open your desired image editing program.
Hold down the "Ctrl" key and then hit the "V" key to paste the screen shot. The captured image appears on screen for saving, editing and sharing.