This tutorial will show you how to change the profile of your connected network between
public. Depending on this setting, your sharing preferences will change with the
home network being the most sharing friendly with computers being discoverable and files being shared, and the
public network being the most secure with your computer not being discoverable and file/printer sharing disabled.
Right click your connection (in this case a wifi connection) in the bottom-right of your screen and click "Open Network and Sharing Center".
You will be shown the following window. The text/link indicated will tell you what the current profile is for the network you are connected to. If it is not what you desire click the text.
In the window that now pops up, click the appropriate network type for your current network. If you are in a hotel or internet cafe, make sure to click