I just put up a blog post on how to do this but thought I'd stick it up here in case anyone is interested in getting mad catz cables to tentatively work under xp! It works but I have had to reinstall the mad catz software each time I want to have a session transferring images.
Here is how I got it working this is based on numerous forum posts and collected stuff from around the interweb,
Turn on your PC and hold down whatever key you need that takes you into BIOS (f2 is common)
In Bios find your parrallel port settings (under "advanced" tab possibly) set your Parrallel port to "EPP" and make a note of the IO Range (mine was 0378)
Save changes and boot
Install the Mad Catz software but don't run the software yet
Unzip all the contents of the Porttalk folder you downloaded into the Mad Catz folder that was created when you installed the software...this would be something like C:\Program Files\Mad Catz\Camera Link Software\
Then open a command prompt..click start, run and then type "cmd" and hit enter
In the command prompt you need to move into the directory you just placed the porttalk stuff in by typing;
CD C:\Program Files\Mad Catz\Camera Link Software\
then hit enter
then type;
AllowIO cls.exe 0x378
Note the last bit of that statement "0x378" that refers to the IO Range we noted before so change this to the value that you noted from your machines BIOS placing an x after the first digit.
Then open the Mad Catz software, it will ask you to set the range for your parrallel port so select the number that matches your IOrange again...it will then ask you to select a paint program to edit the images, you can select one or cancel this.
You should then be able to download your images.(you need to read the gb camera instructions on how this works! basically you select a image in album and print it from the gameboy)..but unfortunately I have had to go through this proccess every time I want to download images as it only works for one session...not to bad if you have one or more gb cameras full of images ..but a bit of a pain if its for just one picture!