How to Take Screenshot without Rooting

Requirements:
An android device
A computer with Windows OS

androidandros.blogspot.com

Procedure: 

• Enable debugging mode on your phone in settings> applications> development
• Download This app and install to your Phone. password to archive is: androidandros.blogspot.com
• Download This archive and extract To your PC. password to archive is: androidandros.blogspot.com
• Connect your phone to computer via USB cable.
• From extracted folder double click on "install.bat".
• Wait till windows command prompt shows "daemon started successfully".
• Now open screenshoter app on your phone.
• Select the delay time you want.
• and click on take screenshot and screenshot will be taken at the end of delay time.

You can alternately try holding home key and the holding and releasing power key whilst still holding home key to take screenshots.