To take a screenshot on a Windows Phone device running 8.1, press the power button and volume-up key at the same time. If you're having trouble getting the timing just right, hold in the volume-up key, then press the power button. I found this alternative method to work for me without issue.
Your device will instantly take a screenshot, alerting you it was successful with a shutter sound, and save it to a specific screenshot album in your Photos hub. From there, you can share, edit, delete, or do whatever you'd like with the captured screen.
For those waiting for the 8.1 update, you can take a screenshot by pressing the start and power buttons at the same time. Unsure when you're going to see the update? Dan Graziano breaks it all down for you in this post.
There's plenty of new features in Windows Phone 8.1; this post details 11 of them.
Source : cnet
