fan runs constantly

I have an older computer using windows ME. The fan runs constantly until it is unplugged from the wall. Windows will not start and there is no noise coming from the hard drive. Does this mean that the mother board is hooped? Or could it be a problem with the power supply? The on off button does not have any value at this point even though it is lit up

 

When you connect power, do the fans, etc, start automatically?

"Windows will not start ". Do you see anything on the screen?

I would check that the on/off button is not getting jammed. You can disconnect the power connector to the motherboard (if it happens to be an AT power system where the button connects to the power supply, don't play around with it). The label on the motherboard for the power "switch" is PWR or PWR SW (not PWR LED). If you disconnect that and it does not automatically start up when apply power, the button is jammed on/faulty. A jammed power button might also explain why there is nothing showing on the screen.

Power supply, yes possibly. If it is not a specialized power supply (some Dells have non standard wiring) you could borrow a working one to try.

Motherboard, yes possibly. Try "clearing the CMOS" by removing the CMOS battery for, say 30 minutes. If you can see the model number on the motherboard, find a download of the motherboard manual and check through it. Disconnect any added hardware like PCI cards and drives (floppy, CD, HDD) if you see that drive's LED staying constantly lit.

The power button may be on a 4 second delay which means you have to hold it in for 4 seconds for the system to power off.

Matt
Edit: for a beginner, if that sounds quite technical and you have not worked inside a computer case before, you will need to enlist the help of a computer-savvy friend or relative or work through the information in the motherboard manual carefully.