How to record the sound of youtube on Windows 7?
1. Go to Control Panel -> Sound
2. Go "Recording" tab
3. Right click and "Show disabled device"
4. In the "Recording" tab, there will be a list of recording devices
5. Ensure "Rec.Playback" is selected with a green icon
6. Start Accessories -> Sound Recorder
7. Play your youtbute video while start recording from Sound Recorder
8. After you finish recording, save it as .wma file
9. Open iTunes
10. File -> Add File to Library
11. iTunes will ask you if you want to convert from .wma to .wmv
12. The converted .wmv files are located at C:\Users\<username>\Music\iTunes\iTunes Media\Music\Unknown Artist\Unknown Album