Instructions
Step 1
Android 2.1 to 3.1
Install any screenshot software like Screenshot Ultimate.
Step 2
Android 3.2 and later
Hold down the "Recent programs" button for a few seconds. If it doesn't work, then install any screenshot software, for example Screenshot Ultimate.
Step 3
Android 4.x
Hold down the power and volume down buttons simultaneously for a few seconds. Pictures will be saved in / sdcard / Screenshots, or sdcard / Pictures / Screenshots folder.
Step 4
Samsung Galaxy
Hold the "Back" and "Home" buttons simultaneously pressed for a few seconds. The images will be saved in the ScreenCapture folder.
Step 5
Samsung Galaxy S II
Hold down the Power and Back buttons simultaneously for a few seconds. The images will be saved in the ScreenCapture folder.
Step 6
HTC Desire S
Hold down the Power and Home buttons simultaneously for a few seconds. The images will be saved to the main photo folder.
Step 7
Samsung
Hold down the Power and Back buttons simultaneously for a few seconds. The images will be saved in the ScreenCapture folder.
Step 8
Sony Ericsson Xperia
Hold down the power and volume down buttons at the same time for a few seconds.
Step 9
Huawei
Hold down the power and volume down buttons at the same time for a few seconds. Pictures will be saved in the / Pictures / ScreenShots / folder.