Have you ever looked at one of your folders using Windows 7 and noticed a strange padlock next to it? Have you ever wondered what in the heck that thing is? The padlock probably has several meanings, someone will need to beat the details out of some poor Microsoftie to know for sure, but one thing that it CAN mean is that some of the files in that folder (or sub-folders inside of that folder) have specific security permissions on them that are not inherited from the folders they reside in. In general, that isn't a good idea. You want to own folders, and then by extension anything in those folders. The good news is, there is a fairly easy - if a bit obscure - way of fixing this. You can remove the lock overlay in this case by resetting the permissions to be inherited, and removing all permissions that are not inherited.
Right click the folder, click Properties.
Click the Security tab.
Click Change Permissions.
Check Both boxes to Include inheritable permissions, and to Replace all child object permissions.
Click Apply then click Yes.
Wait for the list to refresh.
Remove all permissions that say "not inherited".
That should remove the Lock overlay.
You may need to uncheck Use Sharing Wizard in Folder Options on the View tab to see the Security tab, and may have to boot to Safe Mode as well, if running Home Basic or Premium.