How to Reset an iPad That Has a Passcode Lock
This is for an iPad that has never been synced with iTunes
Step 1 Disconnect the iPad from the computer, but leave the USB cable connected to the computer.
Step 2 Hold down the "Sleep/Wake" button for several seconds until a red slider appears, and move your finger across the slider to turn the iPad off.
Step 3 Connect the iPad to the computer while holding down the "Home" button to turn on the iPad.
Step 4 Release the "Home" button when you see a message that says, "Connect to iTunes"
Step 5 Launch iTunes, and iTunes will alert you that it detects a device in Recovery Mode.
Step 6 Click "OK" and click "Restore" to reset the iPad.