I quite literally cannot think of a reason not to install Greenshot on any workstation or personal PC where you could ever conceivably need to screenshot something. Greenshot is free, open source, and astoundingly good. By default, the program will bind itself to the Print Screen key under windows, so you initial a screenshot just like normal. The program will then launch a cursor that lets you specifically select the area of the screen you want to capture. Once you have made your capture, you can launch directly in to an editing program and save the grab for later, or export to any number of applications on your PC. Get Greenshot. It's how I'm putting together every screen grab on this site.
Click here to download the software ==> Greenshot