To take a screenshot please go through following workflow:-

1.       Please press the "Print Screen" key from your keyboard

2.       Open Microsoft paint and paste the screenshot (ctrl-v) as shown below.

3.    Save this file as jpeg.

For taking specific screen shot.

1. Please download screen hunter from  
   http://screen-hunter.uptodown.com/en/  and then install it

2. Save path where you want to store your screen shot from folder tab as
   shown below.

2. Please click on capture now.

3. Hold left click and select specific region.

4. Then you will get screen hunter message as below

5. Click on ok.

6. Screen shot will save in specified folder