I have the same problem - I haven't used my GP32 in a while (for shame) but I'm going away next week and always take my trusty GamePark along for games and music en route. I've upgraded to Windows XP since I last connected the little marvel, and now I've reinstalled the PCLink software, it can't open the USB port. It's a port I use for all my non-modem peripherals, so I know its the drivers not the connection.
Trouble is, its been so long since I used the thing (and even longer since I had to do all the installation stuff) that I have no idea where these drivers should be. I've kept a folder of "essential GP32 files" but I don't think it's anything in there. Shouldn't they install with the PCLink program?
Any help greatly appreciated, as while my GP32 still works, there's some crap on the SMC that I'd like to clean off and replace with some new games.