They probably have slightly different hardware to keep a price edge. But anyway, to anyone on HN I'd think bundled software is pretty much a non-issue; I've always installed Windows fresh and I feel like doing that isn't a big deal if you are technical.

Where do you get a free non OEM install of Windows if you aren’t an MSDN subscriber?

If it is Windows 10, you can do so here https://www.microsoft.com/en-us/software-download/windows10 Otherwise

https://www.microsoft.com/en-us/software-download/windows8IS...

https://www.microsoft.com/en-us/software-download/windows7

Well, I am an MSDN subscriber. But if you aren't, can't you get a "recovery disc" from Microsoft somewhere and then use the serial on the label? I can recall doing something like this in the past.