I'm trying to install 42.1 on a HP Compaq nx7400 laptop. This machine has a
hardware button that can turn WiFi on and off. It also has a blue LED indicator
for this.

I wrote the Network Installation .iso to an USB stick and proceeded to install,
the plan was to do it over wireless.

Early on the installation, the WiFi is turned off, remains off and then the
installation system complains that it cannot get an IP.

That stupid hardware button does not work anymore to turn WiFi on again. I have
to go to BIOS and reset to defaults to get WiFi back.

Why would 42.1 turn off WiFi?

I have 13.2 installed on this laptop and it did not do that.

The wireless board is Intel Corporation PRO/Wireless 3945ABG