share isp

i have a road runner connection in the house already. i cant run a lan cable to the location i want to run a pc on the internet easily. i already have a cable for tv run to the outbuilding. can i buy a cable modem and just hook it up? i dont want to rent 1 from rr. i've tried the modem supplied from my isp out there and it works fine. i'm not sure if a store bought modem will ping the isp correctly without the isp's knowledge. i know a router would be the best way to go about this. but running the lan cable would be very difficult. and swithing my whole network to wireless would be far more costly. this is probably an easy problem for you guys to help me fix.

thanx in advance for any help.

mike

The modem you would buy would be the same cost or more than a wireless router.

And no, it wouldn't work. The service is tied to the mac address of the modem.

You cannot have 2 cable modems on the same internet connection.
As MobilePC said get a wireless router and nic card

can you tell me what to buy then. how far will a wireless router reach? i have this pc in an outbuilding. we have a tavern setup in the yard.
thanx
mike

Wireless router will likely give you 300 feet line of sight with nothing in the way basically.
More if you use a booster antena

i have to go thru 2 walls to an outside building which is approx. 60 feet. would this work? thanks

Only way to find out is try
I had the same type of issue.
I put the booster antena as high as I could and it works at about 200 feet