Changing File Encryption Settings on a Windows 7 Home Network
Open the Windows Control Panel, and then click Network and Internet.
The Network and Internet window appears.
Click Network and Sharing Center.
The Network and Sharing Center window appears.
In the left pane, click Change Advanced Sharing Settings.
Windows creates separate network profiles for each of your networks (for example, Home or Work and Public).
Under the profile you wish to change, scroll to the File Sharing Connections section and click Enable File Sharing for Devices That Use 40- or 56-bit Encryption or Use 128-bit Encryption (default). Click Save Changes.
Windows 7 saves your changes to the file encryption settings.