When your iPhone freezes in an application, refuses to close a running application or issues another error, you can end all of the running processes or the process for the problem application in minutes. Start by ending the problem process or clearing the processes on the phone to avoid resetting the phone when it is not necessary.
The iPhone programming includes a key combination that will force a running application to close when executed properly. Touch and hold the "Sleep/Wake" button along with the "On/Off" button. After several seconds, you will see a red sliding bar on the iPhone's display. Release the buttons when the slide bar appears, then touch and hold "Home" until the application closes.
When a forced quit does not end the application, remove the application from the iPhone's "Recents" list. The application should automatically quit when you delete it from the list. To remove an iPhone app from the "Recents" list, launch the list by double-tapping "Home." Locate the app icon and touch it, holding your finger on the icon until the icon wiggles. Touch the red circle to confirm that you want to remove it from the list.
When a forced shutdown and Recents removal fail, restart the phone to clear all of the current memory, ending the application in the process. Push and hold "Sleep/Wake" with the "On/Off" button. When the red sliding bar appears, release the buttons and slide your finger over the bar. Push and hold "On/Off" until the Apple icon appears on the display to turn the phone back on.
If a system reset becomes necessary, the process will kill any running applications and anything in the system memory along with removing your current settings and personal details. Press and hold "Home" along with "Sleep/Wake" for at least 10 seconds. You will see an Apple logo appear to confirm that the process has started. Release the buttons when the logo appears.