|If your laptop has a couple of PCMCIA slots, then yes you could add a new wireless NIC yourself.|
First, find out if you have an open PCMCIA slot. If you do, then price out a decent PCMCIA wireless card. Once you've bought it, you'll have to disable the onboard wireless interface. You should be able to do that in Device Manager (right click on device, choose "disable"). If there's a physical on/off switch on the laptop for the wireless NIC, I'd shut that off too just to be doubly sure.
Then you would plug the new NIC into the slot and let windows find it and install the drivers and it should work.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.