The iPhone 4 is actually a reliable phone. There are hardly any crashes. And yet it may happen that the iPhone or hang an application remains is frozen and unresponsive. The good news: Since the iPhone is actually a small computer, the phone can be reset as well.
With a reset the iPhone 4 is completely turned off and then restarted. To perform iphone 4 reset, follow these steps:
1. Press the Home and the Sleep button.
2. Keep both buttons pressed down until you see on the iPhone screen, the Apple logo. Now you can release the keys.
3. Attention: The reboot may take a while. Leave the iphone 4 lie quietly for several minutes until the restart has been completed.
Please note that after you did this iPhone 4 reset. Your iPhone will revert back to its first setting, and you will lost all new iphone applications. Check next link to buy iPhone 4 without contract