how to update itunes library on pc
1 Go to the iTunes folder that contains the iTunes library files 2  : Windows: Navigate to \Users\ username \Music\iTunes\. 3  Drag the iTunes Library.itl file to your Desktop. 4  In the iTunes folder, open the Previous iTunes Libraries folder. Windows: Navigate to \Users\ username \Music\iTunes\. 2  Drag the iTunes Library.itl file to your Desktop. 3  In the iTunes folder, open the Previous iTunes Libraries folder. 4  Find the file named iTunes Library YYYY-MM-DD where YYYY-MM-DD is the date you updated iTunes (Year-Month-Day).