It sounds like ram problem. Try removing and reseating the the memory modules. Do the same for the Video card as well, if one is installed.
http://www.hardwarecentral.com/hardwarecentral/tutorials/13/2/
I don't believe Award Bios' have a 3 beep code error, so it's probably AMI
http://www.hardwarecentral.com/hardwarecentral/tutorials/13/2/
I don't believe Award Bios' have a 3 beep code error, so it's probably AMI