Microsoft historically released a good OS version at about every 2 major versions... could Windows 10 be the start of a good version at every 3 major release?
x DOS - passable
o Windows 1 - bad
o Windows 2 - bad
x Windows 3.1x - good
x Windows NT 3.5 - good
x Windows 95 - good
x Windows NT 4 - good
x Windows 98 - better
x Windows 2000 - great
o Windows ME - bad
x Windows XP - better than 9x/ME, on par with 2000, eventually long in the tooth and outdated
o Windows Vista - bad
x Windows 7 - good
o Windows 8 - bad
o Windows 10 - ???
The NT lineage was reasonably good prior to Vista (in the context of that OS family). The DOS lineage was reasonable good until ME (again, in the context of that OS family).XP was a significant improvement over the DOS lineage, however, Microsoft had a reasonably good run in the 90s and early 00s.
If you include Windows 3.1x, then why not 3.0? Also if there's NT 3.5, then why not NT 3.1 and NT 3.51?