1. In the drop down box choose “No internet sharing” and start hotspot.
2. After hotspot started , open network and sharing center. Select you active internet connection.(Blue color label)
3. Now, you can status of the internet connection. Click properties button.
4. Now in the new window, choose sharing tab. In the sharing tab, check the box “Allow other users to connect through this computer’s internet connection” and choose “wireless connection 2″ from the list.
4. Click ok.
5. You can now share internet.
For a step by step pictorial tutorial, Visit this Link