I have exactly one windows box in this house and I avoid turning it on but it is a requirement to operate a particular piece of hardware. It takes several minutes before it has completely booted, it runs Windows 7 on what is a perfectly fine machine for that OS.
Highly frustrating.
That's why you get articles like this:
https://news.ycombinator.com/item?id=21831931
And many others besides. Windows can be such a cycle hog. Probably if I installed 64G of RAM and an SSD I could cut it down to something more decent, but I don't use that machine often enough to offset the expense (and never mind driver/installation media hassles, it isn't broken so don't fix it!).
Other machines take on average about a minute or so but they are running Linux, running Windows on them would easily double that.
My daily driver is a T540p (mostly to conserve power) and it works well enough. Not exactly a speed daemon in use but maxed out on RAM (16G), a 2.5 GHz i7 and a fast SSD it doesn't perform nearly as well as my 20 year old self would have expected it to.
OS and browser will happily eat all of that, and I can't use swap because of the audio drop-outs that would cause. If there was a way to shoehorn in more memory I would take it.