I have tried setting my network up between two computers through a
switch/router/hub (whichever you wish to call it), and the client sets up
perfectly. I'm having problems with the host computer.
It connects directly to the Internet, and the client connects to the host to
access the Internet. The wizard allows me to setup the procedures (computer
name, workgroup, file & printer sharing, etc), and it tries to apply the
settings, but it gives the "Cannot Complete Setup Wizard" ending. I've run it
before and had the network working, but I wanted to change a few settings,
and since, I've not been able to set up the network again.

I've also tried to set up the ICS and network manually, but the Internet
connection doesn't give me the options (I use ADSL) to share the connection,
and the network doesn't work manually when I've tried to connect them
together.

My setup is as follows:
Host Computer:
Via Rhine II Fast Ethernet Adapter (Abit KV7 Motherboard)
BT Voyager ADSL Modem

Client Computer:
Via Rhine II Fast Ethernet Adapter (Asus K7VT4A Pro Motherboard)