As you know, DOS OrCAD was and IMO still is much more powerfull and easy to use(except for not having Windows' most important innovation:copy/pase), plust it gives a much better abstraction to the designer... the new Windows softs are just so powerfull that can't be used[well, not litterally], I mean clicking on anything in the schematic or PCB automatically! opens a winow/menu/... containing 100 items/options and that's exactly what the designer(i.e. me) doesn't need. The DOS OrCAD was 'sold' to another company (dunno the name) after Windows dominated the world as part of the 'diplomacy' or whatever of the original company... the second company bought the software just in order not to distribute it anymore... the DOS version was good enough not to persuade the users miggrate to Windows so 'they' did this 'masquerade'. The DOS OrCAD was 'obsoletified'... it was merely a biz decision.