Open up Computer Management (right-click My Computer | Manage will do it), go to Device Manager, and double-click on your network card's entry. On the Advanced tab there will almost certainly be a setting called "MAC Address", "Network Address" or "Physical Address" -- that allows you to override the network card's address with one you specify. Access to that can probably be scripted so you don't have to waste time clicking on things.

Now consider that every frame sent over a network contains two MAC addresses -- that of the source and that of the destination. On a wireless network with MAC filtering enabled, at least one of those will be valid (the other might be another valid client, or it might just be the router's).

Join the two together and you're less than a minute away from defeating MAC filtering.


You can test your security by making your laptop disconnect and reconnect (through the software, not any hardware switch on the antenna). You should get re-prompted for the WPA key, and if you get it wrong you should fail to get an IP address.


As for not being able to access the modem, that's kind of normal. Your router pretty much ignores the modem and assumes the next hop is your ISP. Depending on the router it might be possible to configure things so that you can get to the modem, but I've never put in the effort -- you shouldn't need to configure the modem once it's set up anyway.