Windows 3.1: ~3 million in first six weeks, ~>3 million in first three months, ~25 million in first year.
Windows 95: ~1 million in first 4 days, ~7 million in first five weeks, ~40 million in first year.
These figures represent Microsoft’s own sales figures.
Still don't support the claim that people were mainly updating from DOS without Windows 3.x. Anecdotally I still think almost everyone using DOS by 1995 had Windows 3.x installed as well. Not necessarily a copy of Windows that was the result of Microsoft selling a copy of course.
Yeah those don't match parent's comment.