SRip32 is a very handy grabber. It's very "straight to the point" so you can make a screen capture
(screenshot) in no time. Here you have a direct download link. 
Install: no install needed. Just create a new folder at C:  or elswhere, give it a name 
you like, unzip srip32.zip to that folder, create a shortcut for SRip32.exe to Desktop 
and you can start using it. 
Run SRip32, go to > Options > Configuration and make it as shown in Pic 1.

    pic 1

   pic 2

 Start  capture                                                       pic 3                                                                       End capture

Click the button shown in Pic 2 and a cross-like pointer shall pop. Move the mouse Up-Left where you wish 
the capture to start, press L button, drag it toward the Down-Right, where you wish the capture to end and 
release the L button. See Pic 3 . 
To save this capture, go to File > Save As > GIF; browse to a location (Desktop, for example), give a name 
and Save. This will make small and crispy pictures for almost anything like: files, folders, menus and other 
computer stuff which have by default 256 colors. For captures of portions of another pictures, a landscape or
some flowers, for example, which have usually more colors, save it as BMP or JPG file. 
 

good luck 

Stefan