This problem may not be as bad as you think it is.
The folder properties will show "read only" even if there is only one read only file in the folder.
The thing is there always is a read only file "Desktop.INI" which is also hidden. This tells explorer
how to display the files.
What you could do is open a command prompt in that folder and give it the following command:
attrib -r -h *.*
This should expose and take the read only flags off everything in the folder for you.