I wrote:
> I have been trying to install 13.1 64bit on a Dell Precision M4600 (it had
> 12.3 running with no problems at all). Tried 2 different discs which
> provide the right checksum.
> Here are the problems:
> 1. Install appears to go well until the "reboot in n seconds".
> 2. The machine reboots and starts the autoconfiguration, but freezes with
> the top progress bar at 3% and the bottom one at 11%.

I can confirm that the package kernel-firmware does not get selected
automatically in the Software section for this particular computer.

I find this somewhat odd, as the package was selected automatically in
another sony laptop I installed.

Checking this package for installation resolved the freeze and finalises the
installation perfectly!

Thanks to all who replied helping with this issue.