Many things can be more readily accomplished through the command line, even a dos prompt while in Windows, than through the GUI interfaces. The ATTRIB command (Windows Built-in command) should allow you to do what you wish.
(The following is taken from the Windows Command Reference)
Attrib
Displays or changes file attributes.
This command displays, sets, or removes the read-only, archive, system, and hidden attributes assigned to files or directories.
attrib [+r|-r] [+a|-a] [+s|-s] [+h|-h] [[drive:][path] filename] [/s[/d]]
Parameters
+r
Sets the read-only file attribute.
-r
Clears the read-only file attribute.
+a
Sets the archive file attribute.
-a
Clears the archive file attribute.+s
Sets the file as a system file.
-s
Clears the system file attribute.
+h
Sets the file as a hidden file.
-h
Clears the hidden file attribute.
[[drive:][path] filename]
Specifies the location and name of the directory, file, or set of files you want to process. You can use wildcard characters (? and *) in the filename parameter to display or change the attributes for a group of files.
/s
Processes matching files in the current directory and all of its subdirectories.
/d
Processes directories.
Hope this helps, -Ewing