How to update iPad 1 iOS 4.3.2 using wifi or OTA

If you are on 4.3.2 then it can only be updated by connecting it to a computer's iTunes - only when you have iOS 5+ installed can future updates be done directly on the iPad (you will get a Settings > General > Software Update option appear).

If the iPad isn't being recognised by your computer's iTunes then see if this troubleshooting page helps : http://support.apple.com/kb/TS1538

Updating to iOS 5+ : http://support.apple.com/kb/HT4972

Have you tried a different cable ?

- Try a reset. Nothing is lost.

Reset iPod touch: Hold down the On/Off button and the Home button at the same time for at

least ten seconds, until the Apple logo appears.

- Look at the dock connector on the iPad, Look for abnormalities like bent or corroded contacts, foreign material and cracked or broken plastic pieces.