I have a android table version 4.4.2 Model number GT90H DualCore-A23 And the word DEMO is showing up in big red letters. Ive tried hard reset, factory reset, I tried going into the about tablet and upgrading my firmware but it gives me no option what so ever to even upgrade it. It was in developer mode which i turned off. Ive tried a few things ive read on internet and im having no luck. Its an old tablet that i bought online. Please help.