net cunnection problem

i have a net cunnection of airtel mobile office i use my NOKIA N72 mobile as a modem my net cunnection getting discunnected after 10sec showing in pc net cunnection discunnected and also showing me this no on my mobile screen D00214555124535.D00555468886456 and many different no i have formated my pc twice for virus and trojen and cheked with antivirus but nothing found plz help