GreenShot Screen Capture – GREENSHOT.EXE
Greenshot.exe is the executable for an Open Source program called Greenshot. This screenshot tool is optimized for productivity. Save a screenshot or a part of the screen to a file within a second. Apply text and shapes to the screenshot. Offers capture of window, region or full screenshot. Supports several image formats. You'll find more information at http://greenshot.sourceforge.net/. This file doesn't necessary need to be running all the time.
Safe
SourceForge.net