I might be wrong, but I believe that you do not need - or even have the ability - to use the GRUB menu in order to boot into the recovery app. AfaIK, it's handled by the BIOS (or some other low-level gizmo). The paperwork that was included when your friend bought the thing should have stated which key (or, possibly, set of keys) es would need to depress after powering up the device. Failing that, a search ought to find it.
The whole point of the "hidden" recovery partition in computers is so that the user can get back to a working (+/-, lol, you said it was Vista?
) OS in the event of a major failure, right? So it would be illogical for the process to require regular software booting. IMHO.
What is the brand and model number (or "number") of the device?
Personally, I'd set up some flavor of linux on the thing if it was mine and I was selling it, especially since it is a netbook. Or if I was dead-set on installing one of Bad Billy Gates' OS on it, I would choose Windows 8 - the time I played with it, I remember thinking it probably would look far more at home on something with a small screen than a real laptop or desktop.