to the forums.
You could try the modem in the other location but you may find you could encounter problems. NTL reccomend that any work on their side of the modem is done by NTL. You may need things re-adjusting.
You can not hook up another NTL modem to the coaxial cable. If you required an additional modem you would have to pay NTL for two modems, plus they would have to come and set it up for you as each modems have to be registered by NTL.
Your best bet would be to leave the modem where it is and get yourself a cheap Linksys Wired Router. Then buy some cat5 ethernet cable and wire up from your router to the location of your other PC.