Well, with so many suggestion i am sure you must have been able to get your music shifted to the desired drive. However, for space management i would you to take a look at small utility named JDisk Report which let you view the exact MB space a folder is taking up, space hogging files. @
here (screenshots attached showing how it works)
Then run a Microsoft disk clean up wizard which you can access after right clicking the desired drive.
Go to control panel, "add and remove programs" and click "sort by last used" and uninstall programs which you do not use longer.
VOILA you have just recovered lots of space !!!
Cheers