In Windows 8, you can take a screenshot of either the entire screen or of an active window. This screenshot can be saved as any type of an image as per your needs. Follow the below given steps for taking screenshot of entire screen, or of an active window:
1) To take screenshot of entire screen: Press “PrintScrn” button.
Now, to save this screen shot, go to, Charms bar –> Click on “Search” –> Type Paint under “Apps”. Click on the “Paint” icon on the left side to open Paint program. Now, press Ctrl + V to paste this screen shot in Paint. Then, click on “File” and then “Save as” to save the picture as a png, jpeg, bmp, gif or any other format as per your requirements.
2) To take screenshot of an active window: Press Alt + “PrintScrn” button. Now, repeat the steps as described above for saving the picture using Paint program.