One thing you should do if you assembled your computer is to take them all apart and put it back together part by part.

First thing is put the memory module/s, turn on the computer if it beeps or successfully boots up successfully. If it does, then put the next piece. Example, the hard drive, then turn your computer on again.

Do the same process until you put all your peripherals back. This is the only way if you don't have an extra motherboard to test if one of your peripherals is damaged or defective and/or if you don't have tools to test your motherboard if it's defective or not.

It's quite tedious but this might help.

damn. i can't find my windows XP cd to reformat. this sucks.