Beep Error Code on POST

When the computer makes those funny sound via the system speaker, it's not doing it because it wants to be heard. The computer is trying to talk to the operator/technician and tell them what's wrong. Almost all motherboards adhere to the IBM BIOS standard beep codes... I think a few OEM's (Original Equipment Manufacturer) have developed their own or use Phoenix or AMI beep codes, but for the most part motherboard manufacturers uses the IBM based ones because they are grandfathered in.

Beep Code:	Description of Problem:
No Beeps	Short, No power, Bad CPU/MB, Loose Peripherals
1 Beep	Everything is normal and Computer POST fine
2 Beeps	POST/CMOS Error
1 Long Beep, 1 Short Beep	Motherboard Problem
1 Long Beep, 2 Short Beeps	Video Problem
1 Long Beep, 3 Short Beeps	Video Problem
3 Long Beeps	Keyboard Error
Repeated Long Beeps	Memory Error
Continuous Hi-Lo Beeps	CPU Overheating

So as you can see, if your computer doesn't start up and starts beeping away like a mime you can start the process of figuring out what is wrong by stopping for a second and listening. From a single beep which tells you everything is okay, to three long beeps which indicate a keyboard error to the siren like Hi-Lo beeps that tell you the CPU is overheating - listening to your computer is good!