new computer-when i plug into usb music will not import...please HELP!!!

my mother in law prchased a new computer...her library is gone and i know it's has something to do with not 'deauthorizing" the old computer...i live out of state and i always like to get more songs on her nano...

i have uploaded a cd and it will not import/sync to her ipod...i have tried everything...i hope it's something simple...on a windows based comp...apple makes it very hard to contact anyone for help...going home tomorrow...PLEASE HELP or direct me where to get help...thank you!!!