The lock icon in Windows 7 indicates that the file or folder can only be accessed by you, and not any other user on your computer. If this is desired, then the lock icon is a good way to ensure that those settings are in place. If this isn’t your intention, then it’s an eyesore.
To remove the lock icon, we have to change the security settings on the folder to allow the Users group to, at the very least, read from the folder.