modem problem

[saurav]

hi guyz,
i am having a very irritating problem.
firstly when i used to switch on my pc it showed that no pci card installed,when i clicked my device mananger it had a yellow question mark on other devices which includes pci card and pci usb bus,then when i clicked on the modems it showed that there is no modem installed and i was not able to go to internet as there was no modem detected,i then uninstalled and reinstalled my modem driver but still no help.
i am having win 98,2ghz,80gb ,256 mb pc.
is it due to that still the registry file of my modem driver prevails in my pc,so the reinstalling is not working,
guyz i had braodband installed on my pc,neither one of them is working,pardon my ignorance does the ill fuctioning of pci card or pci usb can effect the working of broadband
what does the pci card and pci usb bus do.
please help me