The first thing I would do is a chkdsk. I don't know that it will fix it and allow you to mark them as not read only, but its a good place to start.
1) Start.. Run
2) cmd
3) chkdsk c: /f
4) Restart
If you want you can watch and at finish of chkdsk it will tell you if it made repairs to file system.
5) Try again to uncheck "read only"