Windows 98 1st Edition and ICS

I have been asked to setup ICS on a home network and have run into an issue that I just cannot remember seeing before, perhaps my memory is a bit lax here.

When did Internet Connection Sharing become available? Win98SE or was it a part of Win98 original? The main computer that my client wants to share does not have ICS lised under Add/Remove programs. Will it become available with Windows Updates from Microsoft? Or will we have to upgrade to Win98SE?

Thanks