Won't boot after shutdown unless...

I have dell inspiron 1300 wont boot unless I remove the battery and unplug it from the charger then press power button for 1 min and release , then plug the charger only and push the start button normally . the laptop works and boot normally, this long process must be done after any windows shutdown or loosing power for any reason , i like to know waht this long process mean , what is the pushing button for 60 sec do for the laptop ? clears what ?
what is the solution for this problem , please your help is appreciated ,


thanks