When I insert the first of thr four software restore disks in my imac I get a message that says the disk could not be mounted. I have done this proceedure several times successfully but I can't seem to figure out how to make the disks work. I want to do a clean install after having used some recording software and downloading other software etc.. I thank you for any insight that will assist me. I currently run 9.2.2 and the disks will retuen to 9.1 .

eddie slinger