Many users organize their media files, especially those purchased from the iTunes Store, into playlists in the iTunes library. Unfortunately, the content in the iTunes library can't be transferred automatically once you register another version of iTunes on a new computer. To transfer the files, you must copy the iTunes folder. Any files listed in the iTunes library that are not located in the iTunes folder on the original computer will not be copied to the second computer.
Launch the iTunes program on the original computer.
Click the "File" menu in iTunes and select "Library."
Click on "Organize Library" and place a check mark next to "Consolidate Library."
Connect or insert a USB zip drive or other external storage device to the computer.
Click on the "Start" menu and select the "Music" folder. Inside, right-click the "iTunes" folder and select "Copy."
Click on the "Start" menu again. Select "My Computer" and double-click to open the external storage device folder.
Right-click in an empty space within the folder and select "Paste." Your iTunes library contents will be copied to the external storage device.
Open up the browser on your new computer and navigate to apple.com/itunes. Download the iTunes software. The installer will create an iTunes folder in the computer's "Music" folder.
Launch iTunes after installation is complete. Select "No" when asked if you would prefer iTunes found your music.
Close iTunes on the new computer.
Click on the new computer's "Start" menu and select the "Music" folder.
Right-click the "iTunes" folder inside the "Music" folder and select "Delete."
Click on the "Start" menu again and select "My Computer." Double-click to open the external storage folder and locate the iTunes folder that you copied from the original computer. Right-click the "iTunes" folder and select "Copy."
Click on the "Start" menu and select the "Music" folder again. Right-click in an empty space within the folder and select "Paste." Your media library will copy to the new computer.
Open the iTunes software on the new computer. The iTunes library, complete with playlists and ratings, will be displayed.