What a lot of folks don't appreciate (and I apologise in advance to those who do!
) is that flashing a BIOS is not the same thing as updating a program, or installing some new drivers.
What you are doing in effect is re-programming a 'chip' on the main circuit board (motherboard) of your netbook, so you are working down at 'hardware' rather than 'software' level.
It is that much more important therefore to minimise, as far as possible, the chances of anything going wrong, which is why it is recommended that this process be carried out at DOS level, rather than from within Windows.
If the process is interrupted, or fails for any reason, you could easily be left with a non functioning computer, which it may not be that easy to bring back to life again, and could even result in it having to be returned to Dell!
It is not therefore a task to be undertaken lightly!