If you have forgot your Windows 7 homegroup password, then this will show you how to view or print it to see what it is again. You must have this password to be able to join a computer to your homegroup.
HomeGroup makes it easy to share pictures, music, documents, videos, and printers with other people on your home network. You would have had to created a homegroup first before you will have a password to use to join other computer to your homegroup.
1. Open the Control Panel (all items view), and click on the Network and Sharing Center icon.
2. Click on the Choose homegroup and sharing options link.
3. Click on the View or print homegroup password link.
4. Write down this password down, or click on Print this page to print the passoword. When done, close this window.
NOTE: The password is case sensitive, so it will need to be typed exactly as it appears here when used to join a computer to the homegroup.