O damn I want a deal on an iPad 1!
This is a discussion on ipad 1: How to convert demo build to standard retail build? within the iPad General Discussions forums, part of the Apple iPad Discussions category; O damn I want a deal on an iPad 1!...
Did you try to plug the iPad in to iTunes and then hit the restore button? That is the only way I know - and the way the OP solved it.
Demo units from Apple ship with a profile installed that limits what you can do, and removes a number of standard functions. You need to install a version of iOS in Recovery mode to erase this profile.