If your device restarted everytime when you try do something then ur device may infected with virus.There arer many types of virus spread over bluetooth and GPRS with software.
Use fexplorer and go to this path C/system/bootdata if “lib” folder already exist in it then its definetely its a virus and you cant delete this folder and if you try device may restart.There is only one way full format both phone and memory card.But you cant find “lib” folder then problem not very serious.
