Do I have a major problem with my computer. When I press the start button, quite often it will not fire up.?

it could b few diffrent thign. one it could b like the other guy mentoned needs new cmos battery. or might b ur power cord from wall socket to ur computer. or power supply. the power supply could still work and run computer and screen but also b to weak to turn on regurarly it could b slowly goin out. give one them a try, i hope one them works for u. best fo luck!!!