How to Reset My iPhone 3GS
iPhone 3GS is a multi-featured smartphone developed by Apple. Besides the basic calling and messaging capabilities, iPhone 3GS is equipped with a built-in 3-megapixel still camera capable of capturing high-definition videos and images. The phone also offers photo geo-tagging, GPS support, digital compass Wi-Fi and media player. It has a storage capacity of 8GB. The iPhone 3GS has 3.5-inch multi-touch display screen with a resolution of 480 by 320 pixels. If there is a need to reset your device, you can do it using the specified key combination.
Quit all active applications by pressing the "Home" button on your iPhone 3GS.
Push and keep holding the "Power" and the "Home" button for 10 seconds.
Release the buttons when you see the Apple logo on your iPhone's screen. This shows that your device has been reset.