Problems Copying PDF files?

I have a cd of certifications tests and answer keys all in pdf files. I am having trouble making a back-up disc. I have tried CloneCD and BlindWrite. Whenever I attempt to open a copied file I get the error message "...is not a supported file type or has been damaged" (Acrobat). I also tried a pdf password remover program but it didn't detect any passwords on the files. Any help would be greatly appreciated.

I also tried to convert the pdf files to word documents but I wasnt successful with that either

The pdf file might be indeed damaged. Try cleaning the disk.

seem they are damage..

yes it may be damaged

You can try the bad copy professional v3.80.

Try extracting using programs like ISOBuster?

they r damaged

have you considered the possibility that they might be damaged?

After doing a little research I have determined that the issue is not damaged files it is hexalock copyright protection. I haven't found an answer yet but I will keep looking