Here are the steps to save you the hassle of thinking how to create a screenshot:
* When the Error Window is displayed in the system, press and hold your ALT key, then press the Print Screen key located at the top row in the keyboard (usually). Now, release the ALT key.
* The screen is now captured into the clipboard. Next, open Microsoft Paint (type mspaint in Start, Run window) and while in PaintBrush, use the menu option Edit and choose Paste.
* Save the image as a JPG file (preferred, due to it's file compression rate)
While saving the image in Paint, crop the image and remove the white-space surrounding the picture. This not-only improves the look, but also reduces the file size to a greater extent. Always save the image as JPG (from the Save As dialog box drop-down box), unless specifically requested for BMP format. Attach the image file and send it to the recipient.
Thanks to WinxPtutor!