Android Tablet PC reset

Hello, everybody i have one question i have china tablet pc. but every time when i turn on my tablet is all settings reset on default and i must again and again setup clock, language and all other settings than i go on android market install many app but when shutdown tablet pc and turn on again is all settins default and app is deleted what is wrong?how resolve this problem i try with factory reset and with small button on tablet reset button. But the problem there?i have 4.0.3 version on tablet pc please help me!