Record Sound from computer.HELP.

[chanveil]

Well to begin with i would like to say that i am a new user here and i dont know if this question had been previously asked so sorry.
well i have a problem.
My OS is Vista x89 Ultimate with all the recent updates, and my problem is that i dont know how to record sound in Vista.
I knew how to do it on XP with a very simple software like JetAudio, but on Vista its a bit confusing.
To become more clear. I dont want to record from a microphone but from the computer itself. eg some sites that play music. i would like to know how to do such a thing.
Please help.
Thanks...