How to record sounds played from your computer?

Method ONE:
Close the door, turn off the fan, and make sure no sounds other sound is nearby. On the speaker to maximum volume, put a microphone near the speaker, and start recording...

Results: BAD!!

Method TWO:
Get a recording device that comes with an input port. Buy a cable, and connects the computer output to the device's input. Start recording...

Results: WORSE!!

WHY SO MUCH EFFORD?
Here's a better way. No external device required. Records exactly the same quality as how the audio is played by the computer.

Method THREE: (The right one)
First, you have to enable the Stereo Mix from the Windows Control Panel.
Start > Control Panel > Hardware and Sound

Click on Sound Control

In the Recording tab, right click on the blank space and select [Show Disabled Devices] to call out the Stereo Mix. (Windows XP won't need to do this, as the Stereo Mix is already there)

OK, now right click on the Stereo Mix and enable it.

Now, you can record any sound played from your computer with any recording software like Audacity.

Results: GREAT!! Cheers~

More information on Audacity