[nkassis]

I mean what about previous versions of windows? They ran on tablets and desktops. If you mean non-x86 than windows NT initially was going to target MIPS and later became a x86 first(I believe they still released the MIPS version too).

[dagw]

Windows NT 3 could run on (some) MIPS, Alpha and PPC hardware in addition to x86. NT 4 was also ported PPC, but support was soon dropped and only the x86 and Alpha versions got any updates or support. There was even a release candidate of Windows 2000 for Alpha (I think I still have CD somewhere), but it never got a final release.