Root Screenshots not working?

[Willabong]

I have a Tab 2 10.1 updated to 4.2.2 (Not rooted).

I know that you need to hold the power button and the sound button for a couple of seconds to take a screenshot......Tried this several times and nothing is taken?
I look in my Pictures/Screenshots folder, and it is empty?

Am I doing something wrong, or is there a method to taking a screenshot that I need to know?

Any help please, as I need to take several screen shots for a manual that I am putting together!

William.

 

[BRAINZ2013]

Did you select the setting in the setting area .

 

[Willabong]

I didn't know there was one? In settings what heading does it come under please?

 

[BRAINZ2013]

Try the power button and the back button located at the bottom of the device

 

[Willabong]

There is no back button on the bottom of my device. There are only two buttons, the power on button and the volume button? And the back arrow on the screen does not work with the power button either?

 

[Willabong]

I think I may have posted in the wrong area, my Tab is not rooted!