Error #1802

Question

I am trying to use the restore discs to restore my 2580US laptop. All is well on discs 1 thru 3, but when disc 4 (final disc) gets to 79% entire process/82% copying data, box comes up with ERROR #1802 Image file is invalid or corrupt. What can I do to correct this problem? I have repeated restore discs twice and problem still remains.