I have a 3 year old ipad. It is having problems. I want to erase content but it's asking for a passcode. The passcode for the lockscreen PLUS others I always use does not work. I set this passcode over 3 years ago and have no idea what it is. I want to restore to factory settings and fix this but every option I am presented with says "the newest version of iPad software will be installed" How to i restore to default settings without upgrading? Upgrading iOS has ruined every single device I've ever owned - i actually want to use this iPad not render it useless and obsolete? Help?