The first step is to upgrade to 2.0 final (both the player and the emplode software), and install the correct USB driver that came with 2.0 final Emplode (you must manually put it in place, running setup is not enough). Beta 12 did not work with Windows XP on USB. Details here.

Also, if you were running Beta 11 for any length of time, make sure that this didn't happen.

I know you said the laptop has no serial port, so click here.