Windows 7 UI annoyance: remove locked icon
Solution 1:
Have you stopped sharing the folder or is it currently being shared by Nobody?
To check
Right click on the folder and select Properties.
On the Sharing Tab it will say if it is being shared or not.
If it is still being shared click on the "Advanced Sharing" button and untick the "Share this folder" check box otherwise from the Customize Tab click on the "Change icon" button and pick the normal folder icon from %SystemRoot%\system32\SHELL32.dll or click on the Restore Defaults button at the bottom.