What am I missing here?

[Chris Jones]

> Or is there another hidden meaning to this message which I have yet to 
> work out - I mean, I have only ever worked with desktops so is there 
> something about laptops to which message applies?

What it is saying is if you are installing on a laptop (or any machine 
with its own battery power supply), plug it into the mains before 
starting, to avoid the situation where the battery runs out mid 
installation, fubar'ing it up somewhat.

Chris