iTunes enables you to restore iPad to factory settings. Before you start restoring iPad to factory settings, please note that you need to install the latest version of iTunes on your PC or MAC. Then go to Settings > iCloud to turn off Find My iPhone. Now, you can factory reset your iPad with iTunes as follows.
1. Plug iPad into the computer with the USB cable. The iTunes on your computer will automatically launch. If not, double-click the icon to start it.
2. Click the name of your iPad at the upper right corner of iTunes, and then the information of your iPad will be shown. Click the "Restore iPhone" button in the window to start.
3. iTunes will ask whether you want to back up iPad before restoring. You'd better choose "Yes" for the reset will erase the contents in your iPad. Then iTunes will start restoring your iPad to factory settings.
4. Click Restore again to confirm. Then iTunes erases your iPad and installs the latest iOS software. After you restore your iPad to factory settings, it will restart. Now you can set it up as new.
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