I have a couple questions to start with:
1. There should be a sticker somewhere on the board with series of numbers and letters. It should start with either 183617 or 188513. Can you reply with the entire sequence on that sticker?
2. I'm not sure about Windows 98, but more recent versions of Windows will report the PCI device ID throught the Windows Device Manager. If you look in the Device Manager, then select the Details tab, there should be a Device Instance ID selection in the drop-down menu. Select this and it should display something that starts with PCI\VEN_1093&DEV_.... Can you also respond with the rest of the data displayed here?
3. When you look in the Windows Device Manager, how is the PCI-GPIB displayed? It is possible that it shows up as a "Simple Communications Controller".