How to Share Mac Files with Windows Computers
Click the System Preferences icon in the Dock.
Your system preferences display.
Click the Sharing icon.
The Sharing Preferences pane opens.
Click the File Sharing entry.
Your can change your file sharing options.
Click the Options button.
Your user account will display.
Click the user account (or accounts) that will be accessible by Windows PCs.
Snow Leopard will growl while you try to enable SMB sharing. That’s because you have to enable Windows access on the desired account before it can be used. Snow Leopard prompts you for your password, informing you that the account password will be stored in a less secure manner.
Click the Share files and folders using SMB check box, and click Done.
When you click Done, the Advanced dialog, and the System Preferences close and your changes are saved.