Quote Originally Posted by Tellos Athenaios View Post
Yeah but if it is a modem then it is supposed to be used for dial up networking, the cable which plugs in to it “looks” similar to an ethernet cable but it is not an ethernet cable. http://en.wikipedia.org/wiki/Registered_jack Which is only part 1, because part 2 is that dial up networking from behind a router is unlikely to work and part 3 is that dial up networking is unlikely to be covered by customer support of your ISP (and you will need some customer support to get it to work, for one thing you need to authenticate with the ISP).

EDIT: So I guess it is going to be significantly easier to get the wireless working reliably. If your router is simply a few floors of concrete away and you just want a stable connection, a wireless repeater might be what you're after.
I'm not trying to connect via the modem. This computer has an ethernet jack (I've previous been hardwired to my router via this jack) AND a phone jack for the modem. The modem is obsolete and has not been used in years.