Share internet with win7 ?

Hi

I've been gone for a very long time, it feels gooood to be back

I'm having a really annoying problem, I have a network consisting of 30 computers with win7 and one with windows xp.

I have to keep the XP because it has a DVR card which only works in XP

I want to share internet through this XP system and make it my server to control internet traffic.

Right now the modem shares the internet through PPPOE protocol and I want to make it Bridge and create a connection in XP and share this connection in other win7 clients.

I have some info about networking but this one i couldn't crack, the routine methods don't work.

I tried many things, modem's IP is 192.168.1.1

when XP shares internet connection, it changes the LAN IP to 192.168.0.1 and the server falls out of access by clients. when i change the IP back to 192.168.1.xxx range, sharing fails.

when i tried to change modem's IP to 192.168.0.254 and clients to 192.168.0.xxx range, internet on the server is lost

I don't know what else to do, Please help me !