Thanks for your response.
I have no idea what that (sha256 checksum) is but Express burn said the disc was verified after burning. Used 2 brand new DVD-R verbatim discs. Burned at the only speed I think was offered.
In the past, I have installed Ubuntu and several releases of Mint on older laptops and desktops. Now I can only seem to find ISO files of operating systems. I want to help a friend who is not computer savvy at all install a linux distro on his old laptop. Probably Xubuntu for starters. I...