Have you: Turn off ipad - Start iTunes (make sure you have the latest update!) - when ipad is turned off, press homebutton - connect cable between ipad and computer still pressing homebutton - keep press button until itunes tell that it has found a ipad in recovery mode - then follow instuctions on itunes!

If you follow that instruction the ipad will download and reinstall the latest IOS, if that won't help something is wrong and you should go to a service point to get a repair.