If you ask me three tough things to do in Windows 8, I’ll tell using metro start screen, closing metro apps and taking screenshots of metro apps/start screen, you might also would agree with third one. Built-in screen capturing program, snipping tool can capture regular desktop and explorer screenshots but not of metro UI and its apps, if you’re using Snagit here is how to take screenshots of metro apps in Windows 8.
1. While you’re on start screen or using any metro app, press the hotkey (which is print screen button by default),
2. Then press Win key and return to the Start Screen and click Desktop tile (or you can use Win + D key instead) where Snagit will quickly takes you back to the metro screen you want to capture.