What the Coalman says !!!
Try both methods (plug into *line in*, or use USB cord)
One of them should work.
Use Windows Media Player to check and listen to the music.
If USB works, it would probably be the best method.
Audacity: (
http://manual.audacityteam.org/man/Main_Page)
Download the programme, then read the manual about importing from a tape deck with USB.