Windows Explorer does not let one directly get at the read-only attribute of folders from a properties dialogue box.
The "read-only" checkbox displayed in the dialogue box is not the folder attribute. It's a mechanism for changing all of the files within the folder (and, optionally, within its subfolders) to or from read-only. It only changes files, not directories, moreover.
To access the read-only attribute of a folder, one has to use tools other than Windows Explorer, that do let one access the actual attribute flag, such as the
The read-only attribute does not make directories read-only on Windows in any case.
No version of MS-DOS, PC-DOS, OS/2, or Windows NT has ever enforced the read-only attribute for directories. You're being misled by Unix Think. You shouldn't be thinking in terms of "setting 777" and permissions flags, and then looking for equivalent attribute flags. The POSIX user-group-other permissions system has no direct analogue in Win32.
In the Windows NT world, you should be looking at (discretionary) access control list entries. Windows NT has ACLs, and as
billc.cn said you should be adding an access control entry to each file that grants the specific access right to the specific user/group account that needs that particular access to that particular file. There are plenty of ways to change ACLs in Windows, from the properties dialogue in Windows Explorer to the
CACLS command. And there are umpteen SuperUser questions already covering these tools.
The specific access right for the ability to create files in a directory, to grant for that directory by adding an entry to its ACL, is the create files/write data right.
Windows Explorer re-uses the unused read-only attribute bit on directories for its own special purposes.
Since the read-only attribute on a directory has no meaning to the operating system, Windows Explorer re-uses it for its own purposes. If set, this flags to Windows Explorer that it should go looking for a
desktop.ini for folder customizations that alter how the folder is to be displayed.