Device could not be found in My Computer or in iTunes. Device could not be restored"

I have a second generation iPod Touch. It worked fine. Lsat week, when plugged in to put new songs on it, The Device could not be found. Followed all recommendations found diagnostics & apples site and did a reset. Still "The device could not be restored, the device could not be found". It does not appear in "My Computer". Using Windows XP, Vipre Security, Dell Dimension 4700 computer. Any ideas on how to fix?