Well. you probably have to start from scratch.
Disconnect from the Internet, disable ICS, ICF and what ever else is Network related.
Go to Device manger view the Drivers and the IRQ and make sure that there are no conflicts and the drives are loaded correctly.
Connect between the two computers and create a functional Network.
Do not use any wizard or Setup disk configure both computers Network Properties manually.
If you know what to do it should not take more than 10 minutes. If you do not read the content of the links on the page that I gave you in my first post.
Once you have a functional Network configure ICS for Internet sharing.
BTW, if your Internet source id Cable or DSL you will be much better off investing $15 -$39 and get a Cable/DSL Router.
Link to:
AnandTech - FAQ. Basic Options for Internet Connection Sharing
Link to:
AnandTech - FAQ. Hubs, routers, switches, DSL, LANs, WANs...?
Ignore the prices in the links above. The same or similar hardware can be found for 60%-90% less.