When rebooted computer beeps 3 times and will not turn on

Is it a long beep or a short beep? Beep codes are used by the BIOS during the POST to report certain initial system errors.

If you're hearing beep codes after you turn your computer on, it typically means that the system has encountered some kind of problem before it was able to display any kind of error information on the monitor.

Follow the steps below to determine what system problem the beep code is representing.
Difficulty: AverageTime Required: Anywhere from 10 minutes to a few hours depending on the cause of the beep code

Here's How:

1. Power on the computer or restart it if it's already on.
   

2. Listen very carefully to the beep codes that sound when the computer begins to boot.
   

   Restart your computer if you need to hear the beeping again. You're not likely to make whatever problem you have worse by restarting a few times.
   

3. Write down, in whatever way makes sense to you, how the beeps sound.
   

   Important: Pay close attention to the number of beeps, if the beeps are long or short and if the beeping repeats or not. There is a big difference between a "beep-beep-beep" beep code and a "beep-beep" beep code.
   

   This is all important information that will help determine what issue the beep codes are representing.
   

4. What steps you take to solve a particular beep code will differ depending on the BIOS manufacturer.
   

   Choose the correct beep code troubleshooting guide below based on your motherboard'sBIOS manufacturer:
   

   • AMI Beep Code Troubleshooting (AMIBIOS)
     
     
   • Award Beep Code Troubleshooting (AwardBIOS)
     
     
   • Phoenix Beep Code Troubleshooting (PhoenixBIOS)

   Tip: Not sure what brand of BIOS is on your motherboard? See this How To Determine Your Motherboard BIOS Manufacturer guide for some helpful advice.
   

Tips:

1. Still can't figure out what the beep codes mean? Let a community of computer support enthusiasts help out! Post the details of your problem in the PC Support Forum.