How to Keep iTunes Library in Data Drive

iTunes is a media player, media library, and mobile device management application developed by Apple Inc. If your iTunes library has gotten a bit too big for your regular hard drives, it may be time to move it. If you don't want to lose your playlists, play counts, ratings, and other stuff that iTunes keeps in its databases.
 

The iTunes location will be in the System drive (C:) after install. Here we are going to keep iTunes library in another drive (Data Drive) :

1- Open iTunes -> Edit menu -> Preferences -> Advanced tab

2- Check the box "Keep iTunes Media folder organized"
3- Click Change... button to change the location

4- Click OK button (The iTunes will ask you if you want to continue matching the "Keep iTunes Media folder organized" preference, Choose Yes)
5- Go to File menu -> Library -> Organize Library...

6. Check the "Consolidate files" box then click OK

This will copy all of your files over to the new location, keeping your library structure completely intact.

Done!