I think you first need to reveal more about the machine and your 7 ultimate install. I find many of today's owners to install 7 but forget or didn't know to install drivers for the motherboard. In your case that teracom MIGHT BE that USB broadband stick which you get the drivers for from it's provider.
But you first.
i have two OS install in my PC. one is win xp in c:\ drive and another is win 7 ultimate 64 bit OS in e:\ drive.my modem is teracom. from my windows xp i could successfully set up broadband connection and could connect internet but when i try to establish internet connection from win 7 then i am getting error like modem not recognize. i search Google lot to fix this problem but got not useful result. so please tell me someone how could i setup internet connection in my win 7 64 bit OS. my modem is teracom. please discuss in detail.