iphone is disabled

Read the Apple Support document about what to do if you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled. Click here --> http://support.apple.com/HT204306

At the very end of the document it mentions briefly about possibly seeing a request for your Apple ID account information to do this. In order to keep this reply to the point and brief I won't post about strings of eventualities, so post back if you encounter problems should you need to do that.

Which operating system are you using? If you have a Mac you either have iTunes or its newer equivalent in Finder. If you have a PC:

Installer direct download (Mac - only 12.8, and PC) - http://www.apple.com/itunes/download/