I have my PC with 945 Intel mb, Pentium 4 proce. When I switch it on, front panel led's glows continuasly. No blinking as it blink while processing. RAM is OK. Monitor is checked OK with other computer.

I need to know what is wrong in my PC

Can you hear the hard drive spin up? If the hard drive spins up I would most likely think it's the video card. If the computer just turns on and the hard drive doesn't initialize at all, I would tend to think it may be something wrong with your motherboard. One thing I would do, that I have had luck with in the past is. Unplug everything and reset your BIOS. There will be a jumper on the MB with 3 pins, you must identify which jumper it is before you go moving anything, but once you identify it, move it to the position to clear the CMOS, then move it back. I think it has to stay for like 5 seconds in the clear state. It might boot right up after that.

I installed a new power supply in an e-machine windows xp. Previous supply went bad. Power supply runs but no display. Not sure what is running?

Is there anywhere that might show where all the plugs get attached?

Is there anywhere that might show where all the plugs get plugged in and the jumper your speaking about?

What if the hard drive is not spinning up?

what if the hard drive is not spinning up?

Then the power is not present (connector not tight?) or the signal cables are not connected properly or the motherboard is toast.