Did you change to VGA before trying to update the drivers? Some drivers need to be in VGA mode to be able to install, read the documentation with your drivers.
While this is not a PCI card I suspect your PCI bus is not correctly installed. Do you have a Yellow Exclamation Point in your device manager for the PCI Controller or PCI Bus?
Right mouse on "My Computer" select properties and the Device Manager tab for Win 98, Control Panel for Win2K.
If there is a Yellow Exclamtion Point you will need all your drives (possibly a resource CD from manufacturer). Delete that component and refresh or reboot. It is also possible that some other PCI device has this yellow exclamation point saying it is not properly installled orr there isa conflict.