I have used my serial number on multiple machines over the years, and with different cables, so I don't think it's locked to a specific cable, or requires internet access to activate.
If getting hold of a new copy of EvoScan and a cable proves troublesome, then there are a few of us around who have the cable & software, off the top of my head there's myself in Nottinghamshire, @
Davezj in Manchester, @
foxdie and @
Nick Mann in Birmingham - if any of us are nearby enough to meet up, we'd be happy to assist in getting your idle screw re-adjusted to the factory pre-set position to allow the stepper to work correctly.