Hi Guys, I'm totally new to all this android stuff, my sister gave me a cheap Chinese Tonbux tablet that works fine but has the word DEMO in red right across the screen, she bought it off the Authorized seller on amazon a while back and it's out of warrantee now, I tried the tonbux website but they don't reply to my mails and the links on their support section don't work also the model isn't even listed on their site. my sister said it had a problem with the sound and when she did a factory reset that's when the words demo appeared. Anyone know what the problem is with it, I think a good start would be to flash the firmware and re install the os??? can anyone direct me to the firmware and how do I install it? Incidentally I have access to 2 other tablets of the same make my dad and brother in law both have one. would it be possible to dump the firmware from one of these? the specs are below. Tonbux Model GT90H Processor-A23 Android Version 4.4.2 Firmware Version 4.4v2.0 Regards, Chris.