here's a click-by-click-guide i found. perhaps this helps...
5) Installation USB Driver (this part produced by Game Park)
<Windows 98>
1. Turn on your GP32 machine and connect the USB cable with it.
2. Then, Windows 98 will find GP32 machine and show following message box.
And click “next” button.
3. Select “Search for the best driver for your device. (Recommended).” and click “Next” button.
4. Now you should select the location where the proper drivers are. As default, these drivers are stored in the folder “Drivers” under the location where you installed GP32 PC-Link Host application. After the folder highlighted, click “Next” button.
5. Now you can check the driver file is selected. Click “Next” button. Then Windows 98 will show following message. Click “Next” button. The Windows 98 may install this driver.
6. Click “Finish” button.
<Windows 2000>
1. Turn on your GP32 machine and connect the USB cable with it. Then Windows 2000 will show following message.
2. Click “Next” button.
3. Select “Search for a suitable driver for my device (recommended) option and click “Next” button.
4. Select only “Specify a location” option and click “Next” button.
5. Click “Browse” button.
6 Now you should specify the location where the driver files are. GP32 USB driver files are stored in the folder “Drivers” under the location where you installed GP32 PC-Link Host application. And click “Open” button.
7. Click “OK” button.
8. Now you’re ready to install the driver. Click “Next” button then Windows will start to install the driver.
9. Installation completed. Just click “Finish” button.