When you installed the Guest Additions, you added support to Windows for sharing folders with Mac OS X. Before you can use this feature, you must turn it on and configure it, as follows:
If the Windows virtual machine is running, shut down Windows.
Select your virtual machine, click Settings, and click Shared Folders on the toolbar (Figure 9-9).
Figure 9-9. Use the Shared Folders pane of the Settings window to add shared folders to your virtual machine.
Click the icon. The Add Share dialog appears. ...