I purchased a PCI USB Dual Port P/N:234490 from CompUSA:
USB 2 Port PCI Card
Manufacturer: FMI
Mfg Part #: 10190276
CompUSA SKU: 234490

and upon installing the card I get the following error in the device manager:

USB Root Hub Properties
NTKERN.VXD device loader(s) for this device could not load the device driver (Code 2.)

I am running Windows 98 on a Gateway P5-90 XL.

I have the full version of 98 on CD, not an upgrade, and I was using the correct path of D:\Win98. One of my problems may be that the Win98 that I have on my computer is an older version of the one I have on CD.
I borrowed this 98 CD from work so I could get the drivers for this USB.