Add a Mac to a Homegroup in win 7

1. Create a Workgroup. Because Homegroups are limited to computers running Windows 7, trying to connect a Mac to one is usually pointless. Instead, creating a Workgroup will allow you to connect. Workgroups do not automatically enable as many features as Homegroups, but you can still achieve the same functionality through manual tweaking. To create a Workgroup:
2. Go to the computer running Windows 7. Click on the "Start Menu," right-click on "Computer" and select "Properties."
3. Go to the tab labeled "Computer name, domain, and workgroup settings" and click "Change Settings."
4. Go to "Computer Name" and click "Change."
5. A box should pop up named "Computer Name/Domain Changes." You will see the name of the Workgroup you are a member of or you can create a new one.
6. Add your Mac to the Windows 7 Workgroup.
7. Go to the "System Preferences" pane and click on "Network."
8. Click on the "WINS" tab and make sure that the Workgroup name displayed is the same as the one you set up on your computer running Windows 7.
9. To make sure your Mac can share files with Windows, go to "System Preferences" and click on "Sharing." Follow the interface to change permissions on the folders that you desire.
10. Connect your Mac directly to your PC. If you have several Windows 7 computers on a Homegroup and you need to connect your Mac to only one of them, there is another solution that doesn't involve changing from a Homegroup to a Workgroup.
11. Make sure you're on the Mac's desktop. Click on "Go" on the menu bar at the top of the screen. Select "Connect to Server" and type "smb://computersname" in the dialog box. Replace "computersname" with the name of your Windows computer (following the steps to create the Workgroup on Windows will also tell you your computer name).
12. When it asks for your username and password, type in your WINDOWS username and password. You should now be connected.