For WMP to sync to an MP3 device, Windows first needs to properly recognize the device and it should stay connected continuously. It sounds like that isn't the case on your PC. Because this is more a hardware-related issue, I suggest that you repost in the
Windows 7 Hardware Compatibility forum:
http://social.technet.microsoft.com/Forums/en/w7itprohardware/threads
Tim De Baets
http://www.bm-productions.tk