The C:\Users folder is shared when any sub folders from C:\Users\<username>\ is shared
Applies To: Windows 7
When a C:\Users\<username>\<folder> subfolder is shared using the shell UI, the C:\Users folder and its contents are shared as well. Additionally, when sharing is revoked on C:\Users\<username>\<folder>, the C:\Users folder remains shared. This behavior occurs in both Windows Vista and Windows 7.
When any folder or file within a user’s profile is shared, the Windows sharing engine creates a single share to facilitate sharing out that content. This helps facilitates several sharing scenarios. It facilitates scenarios which allow the sharing of individual files while also reducing the management overhead for creating and maintaining multiple shares on the computer. It also allows standard users on that same computer to share their own content without the need to create additional shares, which requires UAC elevation.
Additionally, both Windows Vista and Windows 7 use a Server Message Block (SMB) feature called Access-based Enumeration to limit what content is shown to others when they access this share. With the Access-based Enumeration feature enabled, users accessing the share are only shown the content they have access to over SMB and everything else is hidden from them.
If multiple users exist on your computer, then you will not be able to see the contents of their C:\Users<username> folder unless it was explicitly shared with you even though it is in the same local directory structure. Likewise if your data has not been explicitly shared with others, then it will not be exposed to other computer users via the share.
Additionally, you will be able to see all the C:\Users<username> for users with a local user account that are currently connected and authenticated to your computer from a remote location. While this is occurring, Access-based enumeration will show them everything that they have access to on your computer that is exposed via your C:\Users<username> share. This is by design, as it facilitates the user in getting access to their profile content stored in computers they have accounts on.
This is expected behavior for sharing content from within a user profile in on Windows Vistaand Windows 7. There is no workaround available.