Yes, any pc can act as ad2p, under the following requeriments:
-sound enabled on pc (supposed!)
-a bluetooth dongle with broadcom chip (only some branded carry this like d-link and msi, among others) with original widcomm software
having this only have to connect the dongle, wait the windows message and you say that install the driver later, then goto
www.broadcom.com, support, bluetooth, download the btwinitialupdate archive, run it and itself will download the neccesary sofware, 5 series for winxp and 6 series for winvista.
after installing and rebotting the pc, pair the pc with the device, include the ad2p service, invoke it with the device (set as wireless stereo order) and put any mp3 on device and you're ready!