How to take screenshots on your unrooted Android phone -- Windows version
This first step is the most difficult to get right. On your Windows PC, download and install USB drivers for your particular phone model. You can usually find the USB drivers for your phone by going here. If you're having trouble installing the drivers, try google searching: "install adb usb driver for [your phone model]". Some drivers require you to restart your computer after installation, so be sure to do that just in case. If you are still having difficulties getting the right drivers, you should be able to get the right drivers by installing DroidExplorer onto your computer by going here.
Restart your phone.
Once restarted, enable "USB debugging" on your phone by going to Settings > Applications > Development > USB debugging.
Plug your phone into your PC using a USB cable. If a message pops on your phone up asking to "turn on USB storage", do NOT do so.
Start the "No Root Screenshot It" app on
your phone.
Download and install the "Screenshot It Enabler" desktop application onto your Windows PC by going here.
Run "Screenshot It Enabler" on your Windows computer and click the "Enable Screenshot It" button. If the button is not enabled, try restarting your windows computer.
That's it! You can now unplug the usb cable and take screenshots on your phone using the No Root Screenshot It app on your Android phone. The setup steps you performed will be valid until you reboot you phone.
You should be able to get the right drivers by installing PDANet onto your computer by going here.
If that does not work, install DroidExplorer onto your computer by going here.
How to take screenshots on your unrooted Android phone -- Windows version