Error message for Acrobat Reader and DC

[#1]

When trying to read pdf files from my external hard drive on a new computer I keep receiving this error message (and I am unable to view the files): "There was an error opening the document. Access denied"

[#2]

When trying to read pdf files from my external hard drive on a new computer I keep receiving this error message (and I am unable to view the files): "There was an error opening the document. Access denied"

[#3]

What happens if you copy the files on to your desktop first? Do you get any special message about permission when copying?