Try this:
Click Start, and then click Help and Support.
Under Pick a Task, click Use Tools to view your computer information and diagnose problems.
In the Tools area, click System Configuration Utility.
In the right pane, click Open System Configuration Utility. This opens the System Configuration Utility.
Click the Services tab.
Make sure all the following services are turned on. To turn on a service, click to select the check box.
Application Layer Gateway Service
Network Connections
Network Location Awareness (NLA)
Plug and Play
Remote Access Auto Connection Manager
Remote Access Connection Manager
Remote Procedure Call (RPC)
Telephony
Click OK, and then click Restart.
After Windows restarts, rerun the Internet Connection Sharing Wizard.