optimum settings for record

hi guys.
i am new in this forum.
according to the suggestion of my friends i download the audacity latest version yesterday
i want to record a musci that play in my computer.
what is the best settings?when the record was finished the saved file had very low quality

You mean you want to record internet music, right? Very low quality almost always means you were recording your laptop microphone listening to your laptop speakers. Neither of those is particularly high quality and when you put them together it can be pretty nasty.

The best way is to get the computer to capture the work before it becomes an audio signal – capture when it’s still a bitstream.