Windows x86 we cannot just be recompiled like Linux applications. Linux apps are coded with portability in mind.

Win x86 code will be PORTED with long, hard work to ARM.

Yes, I know performance won’t be great, but it doesn’t need to be. You will not try to use Autocad or Photoshop under emulation (these modern commercial applications will have ARM versions), you will only try to use those old legacy application you have been carrying for 15 years. And those old applications will run perfectly fine at a Pentium 75 level of performance.

Besides, Win32 API calls will be executed natively under ARM processors, so this will improve emulation performance. And most importantly, modern ARM Soc’s haves complex programable GPU’s, windows could use them to speed up x86 emulation a lot.

Maybe Microsoft can automate the process of porting Windows x86 apps to ARM, perhaps some simple apps can be a simple near one-click recompile process while for the other more complicated apps Microsoft can invest as much as they can in trying to make the porting process as simple as possible. Obviously rethinking the app from the ground up for the power saving advantages of ARM is better, but perhaps Microsoft can build it into their development tools, be it visual studio, plugins for eclipse, however its called those platforms developers most use for Windows apps, Microsoft can try to automate the porting process, can’t they?

Very easy: unix software has very long and reach tradition of portability. As opposed to windows, where all APIs are too tightly tied to x86. That’s why Windows and its apps still suck on x86-64, which is just slightly different from x86-32. ARM is in turn completely different platform, although also 32-bit.

How come all the 30 thousand Ubuntu apps just recompile nearly automatically?