Q: Hi. I set up a music folder on my external hard drive that is connected to my asus router.  I can now access the music through my media centre.  how can I update the folder when I make new purchases from iTunes easily without doing it one by one

You could use a backup tool which updates changed files only.  You do not say what kind of computer you use.

You could change it so iTunes actively uses the media on the external drive. Simply copying media to another drive does not make iTunes use it there.  iTunes is probably still using the media on your internal drive.

It could either be set up to put the whole library on the external drive, or it could be set up to only use the media folder on the external drive.  There's advantages and disadvantages to both. I am not so familiar with network drives but it may be slightly faster if you keep the main library files on the internal drive.

iTunes for Windows: Moving your iTunes Media folder - http://support.apple.com/kb/ht1364

See also Make a split library portable and Backup your iTunes for Windows library with SyncToy. You should maintain at least two copies of your library. SyncToy can be used to keep them in sync.

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