Cannot update iPad 4.3.3 to ios6

See Here...

http://support.apple.com/kb/HT4972

OR...

Connect to iTunes on the computer you usually Sync with and “ Check for Updates “...

If an Update Appears Install it...

See the Using iTunes Section Here...

How to update your iPhone, iPad, or iPod touch

Update it from iTunes on a computer as described at the bottom of this article; devices running an iOS version prior to 5.0 can't be updated straight from the device.

(82758)