Does your computer recognise the hardware? If it doesn't recognise it all it might be a bad PCI slot or a bad card. If it does, you may need to install the driver for it (which really should have been done before you installed the card).
You need drivers, end of story. Put them on a cd unless you have it already and install. That is always the hardest part. I would rather having a lan cable running through my house then use wireless, just like now.