Internet And Xbox Live Really Slow Help Por Favor Amigos?

OK so ill give ya the layout. I live in a 3 story house its very old with my room bein on the second and our internet modem box thing downstairs, that is the only place our internet can go cuz its not through the phone cables its with the cable cable we got mediacomm so these past few months i have been playin live through my laptop piggybackin it off of it.But my internet is only one bar reception in my room up here, and i have to turn my firewall off for live if i want an open nat and be able to download xbox live updates. My question to yall is should i get the xbox wireless adapter for the 360 to help my connection? Or since its bein too far from the modem what can i do to boost my range/ connection?