Win98 DOES have a network. As does ANY computer that can connect to the internet directly. If you set NOTHING up, or you want the ULTIMATE in network security, just set it up as your default loopback IP:
127.0.0.1(aka localhost or [local] or LO or loopback)
That is a standard that ALL network CAPABLE systems have. Of course, if ANOTHER computer tries to connect to yours using 127.0.0.1, it will FAIL! Their computer will intercept it and try to connect locally.
BTW, 127.0.0.xxx will ALL go to the local system. 127.0.0.1 is just the only one setup by default.
BTW, accept the default port. Others will work, but the default will help in the future.
I set my own laptop up like this, and my website is copied to 127.0.0.3 on my computer. Nobody could connect to this from the internet, and it works fine for me.
Steve