Windows 8.1 has a feature that not many people know about. You can press Win-PrtScr to take a screenshot and save it straight to the hard disk. The screenshots are saved in the Users/Homer/Pictures/Screenshots folder. This is a very useful way to take a screenshot and save it straight to the disk without having to mess around with paint to save the image ready for uploading to the web. I just wish this worked when capturing a single window. But you still need to use Alt-PrtScr for that.
If you want to use a Powershell script to screenshot your Powershell window, this script will suffice: http://rkeithhill.wordpress.com/2013/10/20/powershell-tidbit-capturing-a-screenshot-with-powershell/. This script will capture your Powershell window to a BMP file.