You need to install Families Sync on your PC in order to convert Legacy family files to the format required by Families and to transfer them to and from your mobile device.
Click here to download and install Families Sync using a standard Windows Setup
Existing users of Families Sync may have downloaded a ClickOnce setup, which is still available from here. As we have encountered a number of ongoing problems with Microsoft’s ClickOnce technology, we have changed to using a standard Windows Installer setup as the preferred installation method. The ClickOnce installation will continue to be available for some time, but will eventually be discontinued. If you installed using ClickOnce, we recommend that you uninstall Families Sync then reinstall using the link above. When you run Families Sync, you will be notified if you are using a ClickOnce installation.