Meh, so frustrating this Bitcoin thing......a fair few years back, I built a machine purely for folding and had accrued around 2.5 bitcoin. Got fed up with it when the calc time started to really ramp up - when the world and his/her dog came onboard, and forgot about it.....then saw, a year or so back, how much Bitcoin were suddenly worth and went to look at my 'wallet'....but had upgraded OS, changed motherboard and all sorts so, to cut a long story short, no access/record remained
D'oh!