Incorrect. Either someone can't count or they are acting like they know something when the list actually reveals ignorance. Until XP, NT and 9x kernels were two different worlds. Windows NT and Windows 2000 were not intended as consumer OSes and do not count.
The only reason MS didn't jump consumers straight to Windows 2000 instead of Windows XP was because Windows NT 4.0 before it didn't support Plug and Play and none of the Windows 95/98 drivers were cross-compatible. That's why they came up with universal WDM for Windows 98SE and Windows 2000.
The problem with Windows 98SE was that it still worked the same with Win9x drivers so there was no incentive for consumer device makers to create and use WDM drivers. They kept making their VxD drivers and such that would not be compatible with Windows 2000, so selling 2000 as an upgrade to 98 could not work. They had to make WDM drivers a requirement somehow long enough before the release of Windows XP so that we'd get WDM drivers for every major device before switching consumers to NT core. That meant shoving stop-gap WinME down our throats. It required WDM for Hibernate and other advancements and nixed enough DOS underpinnings to finally force a transition to WDM from hardware makers. OEMs finally insisted on WDM drivers for all new system components. In a year's time, we were ready for Windows XP. People like to rag on MS, but I say: GOOD JOB. 9x was well beyond its life expectancy. Good riddance.
Now, "Windows 1" does not refer to Windows 1.0 any more than Windows 10 refers to Windows 10.0. It's a name, not a version number. Windows 1.0 was really just a glorified MS-DOS application that wasn't really sold with new PCs as a primary OS. Windows 3.1 and Windows for Workgroups 3.11 were the first to be sold that way and, thus, the true "Windows 1.". 3.1/3.11 is analogous to XP Home versus Pro where Pro is meant for more advanced networking and business desktop use (Pro can join domains), thus they are collectively the first in this series of numbered consumer Windows versions.
1. Windows 3.1 and Windows for Workgroups 3.11
2. Windows 95; A, B, C, and IE4.0 Desktop Update (originally didn't support USB or FAT32)
3. Windows 98/Windows 98 Second Edition; 98SE was analogous to Win95 OSR2+ (original didn't even have USB Mass Storage drivers built in).
4. Windows ME
5. Windows XP and XP-64
6. Windows Vista; WinFS wasn't ready and performance was worse even with Superfetch but they got away with forcing it on gamers by withholding DX9. Aero Glass was cosmetic.
7. Windows 7
8. Windows 8/Windows RT (analogous to XP/XP-64)
9. Windows 8.1; Clearly MS was considering making Win8 the last stand-alone version but wasn't committed enough to forego the possibility of selling something else with a full number if they couldn't shake Win8's stigma.
10. Windows 10; People clinging to Win7 aren't going to switch to Win8/8.1 just because MS offered all future upgrades for free. They need something clearly new (can't be just be "8.2") with even more concessions to traditional desktop users.