Can I setup a cable modem with a router

I have been using the Netgear WGR614V7 router with a DSL modem for about 4 months. The router works fine, but now I'm planning on switching to cable for my Internet service. My computers are located on the second level of my house, but the cable is on the lower level where I have my TV sets - I don't have a cable connection on the second floor. Is there a way I can use this router with a cable modem on the first floor to transmit Internet signals to my remote computers on the second floor? One computer uses Windows Vista while the other uses Windows XP and they currently work fine with the router connected to a DSL line (except that it is slow). Any suggestions you can make will be greatly appreciated.

Joe