Open iTunes on your Mac.
Click "iTunes" and open "Preferences."
Click the "Advanced" tab.
Click "Change" next to the "iTunes Music Folder Location" heading.
Select a folder on your computer in which to consolidate all of your iTunes music.
Check-mark the box next to "Keep iTunes Music Folder Organized."
Click "OK" to exit the "Preferences" menu.
Click "File," choose "Library" and select "Consolidate."
Click the "Consolidate" button to confirm this action.
Plug a flash drive into your computer.
Navigate to the folder you consolidated all of your iTunes music into.
Copy this folder and paste it onto your flash drive.
Eject the flash drive from your Mac and plug it into your PC.
Copy the music folder from your flash drive and paste it onto your PC.
Open iTunes on your PC.
Click "File," "Add To Library" and select the folder you copied over from your flash drive. After doing so, the music will be imported into the iTunes library on your PC.