That's really critical. I had a bad disk 4. After disk 3 passed the test, I was about to cancel and just start the upgrade, but I decided to blow another few minutes and test it. If only I had bother to save the files after burning the CDs! I had to download the .iso file all over again.
Agreed, but note that if you have the iso's on the hard disk of the machine to be upgraded, you only need the boot CD and can then use the images on the HD to finish the installation. You'll need to know the partition device name and the path within that partition to the iso's so you can tell the installer where to find them.
