ALL YOU HAVE TO DO IS GO TO YOUR PROFILE DIRECTORY:
C:\Documents and Settings\yourprofile\Application Data\Mozilla\Firefox\Profiles\someweirdlettersand#'s.default AND RIGHT CLICK(ANYWHERE IN THE BACKROUND), CLICK PROPERTIES, AND UNCHECK THE READ ONLY BOX, CLICK APLLY, THEN CLICK "APPLY TO CHANGES TO THIS FOLDER, SUBFOLDERS, AND FILES", CLICK OK, AND YOUR DONE, EVERYTHING SHOULD BE BACK TO NORMAL. BY SPACE.