I might be wrong but I believe that you need to reset the machine while holding down shift-break.
although I could be wrong on how to access it.
THe spectrum has no non-volatile ram, hence once it is powered off, there is nothing that could store information for next power up. I am unsure where your friend got this idea from, perhaps newer acorns at the time had a form of NVRAM? I dont believe Amstrad's did either, nor any commodore (non x86) machine for the time either.