Hello there, Underwriter.
The following Knowledge Base article provides in-depth instructions on how to migrate your content to an external drive:
Particularly of note for your situation:
This option requires more work than Home Sharing, but it creates a backup of your iTunes library on the external drive in addition to moving your content.
Notes before you start:
- You can use most iPods as an external drive.
- Windows operating systems don't recognize Mac OS-formatted disks (HFS or HFS Plus formats). Because of this, you can't use a Mac-formatted iPod or external drive to move your music to a Windows PC. See iPod: How to determine iPod's hard disk format if you're not sure how your iPod is formatted.
- Mac OS X can read Windows-formatted iPods and drives. This means there are many ways to migrate your information from your old Windows-based PC to your new Mac.
- Mac OS X: To be sure external drives appear on your desktop, choose Preferences from the Finder menu. Be sure the options for "External disks" and "Hard disks" are enabled.
Thanks for reaching out to Apple Support Communities.