My experience with AOL (not in my own home) is that it's pretty incompatible with most things.
However, the wireless kit in your new machine either can, or cannot, connect to the wireless access point. That in turn either can or cannot connect to your router.
Try the "who am I?" test:
Open a Command window (used to be called a DOS window) - with XP, you click start-run- and type CMD <enter>. I've not used (and will not use) Vista.
In that command window, type ipconfig /all
That will respond with a stream of information, amongst which should be "IP Address". If you have one that looks something like 192.168.x.y or 10.0.0.n then you are connected to the WAP and probably also to the router. If there is no IP address, then you aren't connected.
I take it your router has no wireless facility built in?