How to remove Lock icon from Windows 7 folder?

I unshared a shared folder in my Windows 7 and suddenly there is a Lock icon appear on the folder icon.
To remove the Lock icon, here are the steps that I used:

1. Right click the folder and choose Properties.
2. Go to Security tab and click Edit.
3. Under Permissions for Shared Folder window, click on the Add button.
4. Type in “Authenticated Users” in the field and click Ok.
5. Click Ok to close all the remaining windows.
6. The Lock icon is now gone.