Problems with upgraded system

clean xp install?

That would require the disk drive to open, which is not currently working

The light on the drive doesn't turn on but i can't notice anything wrong with the power connectors. There are 2 connectors coming out of it, there is a wide and thin one that is a band-type one with a lot of pins 2x10 or so connected to the mobo and then there is a small one on the right of it connected from the PSU, the dvd drive and the PSU haven't changed in this upgrade and as far as I am aware I haven't changed the connectors used :S

Argh, wth, haven't changed anything and now when my pc powers up nothing comes up on the screen and after about 10 seconds of me turning it on it shuts down then powers itself up again a couple seconds later continually.

Right yesterday i bought a new disk drive and hooked it up and everything was working, I got into windows and was happily playing games for a few hours. But i come home today and turn it on and it is doing the same thing again, I press the boot up button, the LEDs on my keyboard/mouse flicker on and immediately off again and the computer keeps whirring for about 5-10 seconds then turns itself off, only to boot itself up again 3 seconds later. This will continually go on and on :S

And how do i reset the CMOS/change the RAM settings in the BIOS?

OK i've supposedly reset the CMOS by putting a screwdriver over the reset things for 5 sec but still to no avail, it still continually reboots. I don't know if this makes any difference, but when I turn the pc on, the screen's on light(nothing comes up on the screen either) and the mouse and keyboard LEDs do not light up like they would if it was booting properly, what makes this more frustrating is how i got it to load up fine yesterday by simply just leaving it booting continually for awhile, I went back to it and it was in Windows working fine.

Nope, i dont see how I can do that if the computer doesn't even boot