If you have been using your Apple iPod Touch, iPhone, or iPad for a few years it can start to randomly freeze, or be slow to respond. If the usual solution of restarting the iOS device doesn't solve the problem you can go a step further and reset the device back to its original settings.
Note: This will erase ALL of the email, notes, content, software, and settings from your iOS device. Before you do this you will want to have synced the apps and music from the iOS device to your desktop computer.
Resetting Your iOS device
Step 1. Transfer Your Purchases
Step 2. Erase the iPod
Once you are sure you have a backup copy of your iOS content copied to your desktop computer you can start the process of erasing your iPod. When you reset your iPod and erase all of the content from your iPod / iPhone / iPad the files are PERMANENTLY deleted and cannot be recovered.
Let's start the iOS erasing process.
A progress bar will show the erasing progress. It can take anywhere from 10 minutes to an hour to erase the contents of your iPod Touch / iPhone / iPad. On my 8GB iPod Touch it took about 10 minutes.
Step 3. Connect to iTunes
Once the erasing has finished the iOS device will restart and show an icon that indicates you are ready to connect your iOS device to iTunes.
Step 4. Set up your iTunes Sync settings.
Since your iOS device has been fully reset you can now setup your iTunes settings. This allows iTunes to automatically synchronize your contacts, calendars, and email.
With your iOS device selected on the left side of iTunes click on the Apps tab at the top of the iTunes window. This screen allows you to set up your App Syncing preferences. if you enable the Sync Apps checkbox iTunes will manage the apps installed on your iOS device. You can use the checkboxes next to each app name to install / remove an iOS app. You can also change the position / layout of your home screens on your iOS device using the App tab in iTunes.
With your iOS device selected on the left side of iTunes click on the info button at the top of the iTunes window. The info tab allows you to choose what settings you want to use when you sync your calendars, contacts, and email accounts with your iOS device.
After making changes to the iTunes sync settings click the Sync button in the lower left corner to apply the settings.