Sharing Internet Using Broadband

Lately, I use DSL Internet connection and i have no trouble in sharing its connection because this was connected and installed directly into the LAN card. Few days from now, I change from DSL to Broadband Internet Connection and I have trouble in sharing its connection because it is connected directly into a USB Port rather than into the LAN card.

Now, is there anybody here who can help me in my problem? Do I still have to use two (2) LAN card in sharing? I don’t want to use a Router.

By the way, I installed WinXP OS in my system.

Thanks a lot in advance guys.