Well...XP Pro, with Win 3.11, Win 95, Win 98, Win 98 s/e, and QNX all loadable as Virtual Machines, a second disk caddy of Win XP Pro [as backup]...and a self-contained zip drive OS of Win 3.11 accessed by boot disk.
All 3.11s use Calmira as shell, not exploder...and all 9x and beyond use LiteSTEP as shell [varying vers]......QNX is bog-standard...