I've had some luck fixing these types of problems using the command prompt (start|accessories|command prompt)  I can't mess with this work computer, so I won't be able to try any of the commands.

Anyway, make sure your backup of the folder is good before experimenting.  After entering the command prompt,, type "help" (without the quotes) to see a list of commands.

Anyway, you can globally change a directory file(s) attributes and many things more.  I know Norton is pretty insidious and it's one reason I've quit using it.  The protection is fine, but try removing it if you ever go to anther virus program.