After Microsoft enforced driver signature requirements (Windows 10 v1607+), old KeyMagic (pre-v2.3) simply stopped working. You had to boot Windows with "Disable Driver Signature Enforcement" – a dealbreaker for most.
Brilliant for disabling the obnoxious Windows Key or Insert key before gaming. Old versions let you disable keys globally or per-app (though per-app was buggy pre-v2.0). The Bad (Why you shouldn't use it today) 1. The "Sticky Key" Bug (v1.x) If you remapped Ctrl to Caps Lock and typed too fast, KeyMagic would sometimes "lose" the key-up event. You'd end up typing LLLLLLIKE THIS until you tapped the stuck key again. This was infamous on old forums. keymagic old version
Old versions (v1.2–1.5) had a unique "layer" feature. You could hold Scroll Lock or Caps Lock to turn your J,K,L keys into a numpad. Modern gamers would call this a "function layer" – KeyMagic did it in 2010. Old versions let you disable keys globally or
Use AutoHotkey with this 3-line script to mimic old KeyMagic: You'd end up typing LLLLLLIKE THIS until you