mpc 2500 system problem / can You help?

Hello everybody. I've bought MPC 2500. Everyting works fine but everytime
when I power on, sampler shows window "====== MPC OS UPDATE ====== please insert
memory card". Then I load OS from card. After load, mpc normally shows Main Window,
then I can work without problems. When I turn off mpc and turn on situation repeats itself.
Is it with mainboard/flash rom problem or should I press button combination
to repair it? Regards

Check if the WINDOW button isn't blocked, because system update is initiated by turning the MPC on with the window button pressed.