Comment 85 for bug 192720

@Martin:

Please don't use this. While it does work, it is not a clean way of
doing things. Deleting things is ugly, especially since the next kernel
update will render your system unusable again (since it reinstalls the
deleted files). Also, there is a clean(er) way, which probably should be
documented instead of the 'deleting things way'.

1. Download the ubuntu alternate install cd (mind the 'alternate').
2. Install your system using this (yes, it uses debian-installer instead
of a live cd approach). Write down the chosen root partition
(/dev/sda1 ?)
3. Reboot again from CD and choose: 'Rescue a broken system'
4. Say yes to a couple of things and then choose the correct root
partition (you wrote it down, didn't you?)
5. Execute a shell in the root partition:

# cd /etc/modprobe.d
# vim blacklist (or use your favorite command-line editor)
add the line: 'blacklist b43legacy' (without the quotes)
save and exit
# exit

6. Reboot

Then, hook up to a cable or use a supported usb wifi card, enable
updates, install kernel updates, remove the blacklist line and reboot.
It should work now. If not, re-add the blacklist line and come back.

Good luck!

David