After someone on your network creates a homegroup, the next step is to join it. You will need the homegroup password, which you can get from the person who created the homegroup. When you join a homegroup, all user accounts on your computer become members of the homegroup.
Follow these steps on the computer that you want to add to the homegroup:
Open HomeGroup by clicking the Start button , clicking Control Panel, typing homegroup in the search box, and then clicking HomeGroup.
Click Join now, and then complete the wizard.
If you don't see the Join now button, there might not be a homegroup available. Make sure that someone has created a homegroup first. Or you can choose to create a homegroup yourself.