DSL/cable modem switch

Question

how can I convert cable modem to work on DSL.got modem free but have DSL

Answer 1

If you are talking the router, that can be done, but if it's the actual modem, you can't use a cable modem for DSL and vice versa. The cable modem takes a coaxial cable as its source for the Internet and the DSL modem takes a telephone connection as its source. If you already have a working DSL connection (and a working DSL modem), why would you want another?