Reset My Samsung Galaxy W (i8150)

Step 1:
Make a backup. Be aware you may lose data in the process of resetting your mobile device.

Step 2:

Turn the Samsung off. If necessary pull the battery out and reinsert it.
Hold the volume up button and home button.
Press and release the power button.
The Samsung will show a menu
Select Factory reset by pressing the volume down button
Press and release the power button
Confirm with volume up