When syncing your iPhone, iPad, or iPod touch using iTunes 9 or later, one of the following may occur:

You see an error saying that AppleMobileDeviceSync has stopped responding
The sync completes, but nothing changes on your computer or iPhone, iPad, or iPod touch

Older files on your computer related to OpenSSL, but often included with other software, may cause a conflict when they are in some system locations.

When opening iTunes 8.0.2 or later, some customers may notice a message stating "For best results with iTunes, use a screen resolution of at least 1024×768" as show below. This recommendation is made to ensure that all parts of the iTunes interface will be visible during use.
  

When opening iTunes after connecting an iPod or iPhone for the first time or after a restore you may not be able to locate the "Done," "Continue," or "Accept" buttons as shown below. This is due to the screen resolution of your Mac or PC being too low.

When drivers required by a PC’s USB interface are not installed correctly or are out of date, an iPhone, iPad, or iPod connected to this computer may not be recognized properly.
One or more of the following may occur:

Device does not appear in iTunes
Device cannot be restored in iTunes
An exclamation point appears next to the device’s entry in Device Manager
iPod screen does not display "Do Not Disconnect" screen when connected to the computer (does not apply to iPhone, iPad, and iPod touch)
iPod is not recognized as a disk in My Computer (does not apply to iPhone, iPad, and iPod touch)

Products affected

iPhone, iPad, iPod touch, and iPod (all models)
Microsoft Windows XP
Microsoft Windows Vista
Microsoft Windows 7

If you are using Wi-Fi on iPhone, iPad, iPod touch, or Mac OS X 10.6 or later and you experience unexpected results when using location services, you can refer the respective wireless router administrator to the following URL to update information that Skyhook has about the wireless router’s information:

http://skyhookwireless.com/howitworks/submit_ap.php

Location services information is used when tapping the Location button in Maps on the iPhone, iPad, and iPod touch as well as in other built-in applications and many third-party applications available from the App Store.
Location services information is used when setting the time zone automatically using the current location in the Date & Time System Preferences in Mac OS X 10.6 or later on a Macintosh equipped with Wi-Fi.

You can remove all settings and information from your iPhone, iPad, or iPod touch using "Erase All Content and Settings" in Settings > General > Reset. 
If possible, your device should have a full charge before beginning this process. If it doesn’t have a full charge, connect the device to power and leave it connected until the process is complete.