maybe these will help you :

1). Make ur first computer which connected to the modem as 192.168.0.1 and the Subnet Mask is 255.255.255.0.

2). On your second computer which you wanted to get internet share make the IP address is 192.168.0.2 - 255 , and you should put the IP Address of your first computer on your Default Gateway Address and on DNS you put again the IP address of your first computer.

So those will view like this :

Comp A
IP Address : 192.168.0.1
SubnetMask : 255.255.255.0
Default Gateway : 0.0.0.0

Comp B
IP Address : 192.168.0.2
SubnetMask : 255.255.255.0
Default Gateway : 192.168.0.1

Primary DNS : 192.168.0.1

on starband connection i have enable ICS.I have a another question regarding networking.Starband network connection is getting dynamic ip.But another network adapterwill get ip address 192.168.0.1 subnet mask 255.255.255.0 but default gateway is blank.my question is how this work.
To share your internet connection to another computer you will need some criteria or i call that identity : Your second computer which need the internet share will find the computer which have the internet connection and of course you must make the first computer which connected to the net as available to share the connection to other computer. So u must identify your first computer as 192.168.0.1 and then put your first computer IP Address on the Default Gateway on your second computer who need the internet share.

Hope this will help