Internet sharing over lan

i connect to the internet by bridge method.and i want to share the internet to my laptop as well.the thing is i have to dial it from my computer in order to use question is when i try to enable ICS on one of my lan card it says i have configured one of my network computer on

i could have used the PPOE method,but when i set up my ptcl modem to internet connection runs for few mins and it goes...i have to restart my modem whereas in bridge mode it runs frequent..

i have been successful with the router using PPOEE..but i want bridge method to dial internet on my pc and then share via lan to router ! so how to configure it?