>>> I have tried to run network setup wizard
>>> choosing "this computer connects directly to >>> the internet. Other computers on my network >>> connect to the internet through this computer"
That is not correct. The other computers in the network are *NOT* connecting to the internet through that computer, they are all connecting to the internet via the *ROUTER*, or they should be.
If you didn't have a Router, and that computer was connecting via a USB Modem with "Internet Connection Sharing" enabled on the connection to the Modem, then the other computers would be connecting to the internet through that computer.
>>> I have two little computer screen icon in the
>>> bottom right hand corner of the screen and if
>>> I hover over it it says "Local area
>>> connection. Speed 100.0mbps. Status
In the Properties of the Local Area Connection in the Network Connections folder, there is an option to display the icon in the System Tray. What it is telling you is that your network adapter is connected to the router at 100Mbps.
Basically, to share folders you right click them and select the Sharing & Security option. Similarly, right click your printer and select the Sharing option. The most common cause of being unable to access Folders/Printers over the network is a firewall that hasn't been configured properly to allow access to the networked computers. For setting up a Network Printer in either XP or Vista, have a look at my posting click here