To play music into a chat room using your sound card in Windows 7 do the following:
Step 1: On the bar near the clock you will see a white speaker icon which looks like this: right click on it with your mouse and choose Recording Device and you should see a window that looks like this:
Step 2: Now first make sure you see Stereo Mix in the list if u do skip to Step 4 if you don't then right click with mouse and put a check mark in Show Disabled Devices and Show Disconnected Devices like this:
Step 3: Right Click on Stereo Mix and choose Enable.
Step 4: Right click on Stereo Mix and choose set as Default Device like this:
Step 5: Right click on Stereo Mix and choose Properties and you will see a window that looks like this:
Step 6: Click on the Levels Tab and set the slider to 10 and your should be ready to play the tune so find a room test it out and get ready to move the slider if the song coming across to loud or to low.
NOTE: If you cant seem to find Stereo Mix in the list try looking for What You Hear in the list it the same thing if you don't have any of those you might need to update the drivers for your sound card.
Updated: 05 March 2012