PCI slot dead?

Working with an older (2004) Dell Inspiron 9100 laptop that does not seem to see either of the two new wireless network cards I have tried to install. Is the PCI slot dead or turned off somehow? It can connect to the internet through an eithernet cable and I have two other computers on the wireless network so I know that is up and running. Any ideas? I apologize if this topic is already posted but I couldn't find it.

do you have the correct drivers for the cards installed? and if you do, do the wireless cards come with their own wireless connection software? if so, they can conflict with windows wireless networking causing them not to work, Im assuming your working with XP here. If you dont have drivers installed, then install the drivers, if you do, and they have their own wireless software, try either disabling their wireless network software or disabling windows wireless networking software. If none of the above work, I would then check in your device manager (or even do this first) and see if the computer recognizes somethings plugged in, and possibly trying another add on card (not wireless network adaptor) if you have one available, and see if you can get that to work