When you try to remove the Read-Only attribute from a folder in Windows Explorer, it does not happen. You may even receive an error message.
If you have customized the folder using View / Customize This Folder, Windows Explorer sets the Read-Only attribute, and will not let you change it.
To workaround this behavior, you can make Windows Explorer use the System attribute instead of the Read-Only attribute.
Copy / Paste the following to a <Folder_Path>\CFS.REG file and run Regedit /s <Folder_Path>\CFS.REG: