Unless you're saying that the operating systems themselves are infected (I think someone would have noticed by this point), I always ended up reinstalling the system on the machines I purchased anyway, due the amount of bloatware many have on them. As a result, even if I were to suspect that, it wouldn't be a factor in the end.
But if you do find some sort of malware on a pre-assembled machine - I'm sure you'll have quite a few lawyers willing to take up the case for nothing, as you'll have quite a check waiting for you by the end of the proceedings!
windows is not infected, it is the possible malware!
microsoft can gain access to any networked windows system, via the preinstalled trojan downloading system called windows update.
and you would have no knowledge of it.
let my simplify the question, why are people using closed source?
So anything that has an autoupdater is by default malicious? What evidence do you have that Microsoft is installing spyware, viruses, or other forms of malware on customer operating systems that you so strongly insinuate?
I use closed source operating systems because it's hardly any different from using other closed source software - or do you not use any of that either? Open source is nice, but I'm not going to expect everybody to follow through with that standard (I
have published my own open source software on sourceforge, if that helps to back up my own credentials on discussing this topic). You certainly have the right to despise any operating system you choose - but that isn't a justification for spreading hearsay or other false information.