Vista and older Microsoft operating systems can connect to a Window 8 machine, but only through Workgroup settings, which require a separate configuration setting in the System section of your Control Panel. Remember that only Windows 8 and Windows 7 machines have the ability to join a Homegroup. My conclusion: this is a rare case of the less you know in advance, the easier it is to setup a Windows 8 Homegroup. While years of configuring Microsoft desktops meant that I could setup Workgroups on auto-pilot, creating and joining a Homegroup seemed like learning a foreign language.
My initial reaction to Homegroup was frustration. This page will help you create and troubleshoot Windows 8 Homegroups. The whole point of joining a Homegroup is sharing – giving and receiving access to your friends pictures, libraries or printers.