I told you how to configure the host computer but I forgot the client computer the desktop in your case.
To configure the client computer to use the shared Internet connection, follow these steps:
1. Click Start, and then click Control Panel.
2. Click Network and Internet Connections.
3. Click Internet Options.
4. In the Internet Properties dialog box, click the Connections tab.
5. Click the Setup button.
The New Connection Wizard starts.
6. On the Welcome to the New Connection Wizard page, click Next.
7. Click Connect to the Internet, and then click Next.
8. Click Set up my connection manually, and then click Next.
9. Click Connect using a broadband connection that is always on, and then click Next.
10. On the Completing the New Connection Wizard page, click Finish
Let me know if it worked.
Jonas