Setting up a "F" key for an OS re-install?

Hi,

I've helped people owning Dell and HP PCs use the factory service "F"key for re-instillation of their OS when needed.

I've built my current PC and like the idea of being able to do a re-install from a "F" key when needed also.

I was wondering if Dell or anyone has or is willing to give up the "how" of to do this on ones own PC, to set up a "F" key for the purpose of a total OS re-install?

Anyone's input on this would be greatly appreciated.

Thanks,

John