This timeline doesn't seem correct, since Windows XP came out in 2001, more than five years before Windows Vista in 2006-2007.
Prior to XP, MS had two lines of Windows: the Windows 9x kernels and the Windows NT kernels. Windows XP was meant to be the merger of the two lines, adapting Windows NT to have compatibility with Windows 95 and Windows 98 features. Unfortunately, Windows XP development went overlong, so MS wedged in Windows ME to give a stop-gap release until XP could actually be released.
Perhaps this is why users dislike monthly SaaS - they cannot trust stability of the tool, because often the incentives are to keep adding features well past peak utility [ resulting in enshitification ]