cannot connect to the internet from client PC

intro:
i have a PC running on windows XP and a PC running on
windows 98 SE. i linked both of them together and shared
the internet. the PC with windows XP is the host and the
other one is the client. both computers have seperate
modems.

problem:
i wanted to connect to the internet using the modem on the
client computer when the host computer is shut down. i
tried connecting to the ISP but before the connection is
completed, the computer hanged.
i tried several times and got the same results.