It's often useful to be able to capture all or part of your PC screen, to save for later reference or perhaps to send in an email. While Windows has a perfectly adequate in-built way of grabbing the entire screen or the current window, using the PrtSc key, it's not particularly flexible. Which is why there's a goodly collection of third-party utilities available.
One recent such program is called Monosnap (www.monosnap.com). It's available as a free Windows download, though you can also get it as a web browser add-in and that's the option that I chose.
Not only can you capture a user-defined area of any web page, you can also annotate the capture with text, obliteration etc before it's ready to save, as you can see from the capture below. Then you can either save your capture to monosnap's servers, or to your local PC.
There's even an 8x zoom feature on the Windows version so you can be pixel-perfect when selecting an area to capture.
Monosnap is free. The Windows version is a 3 MB download, which according to VirusTotal is free of malware. Although you may, like myself, wish to start off with the browser add-in as it's quicker to install.