PC laptop and desktop vendors are now clearly hostile parties
You may have heard of Lenovo's SuperFish incident, where Lenovo destroyed HTTPS security on a number of their laptops by pre-installing root certificates with known private keys. Well, now Dell's done it too, and not just on consumer laptops, and it turns out not just one bad certificate but several. One could rant about Dell here, but there's a broader issue that's now clear:
PC vendors have become hostile parties that you cannot trust.
Dell has a real brand. It sells to businesses, not just consumers. Yet Dell was either perfectly willing to destroy the security of business oriented desktops or sufficiently incompetent to not understand what they were doing, even after SuperFish. And this was not just a little compromise, where a certificate was accidentally included in the trust store, because a Dell program that runs on startup puts the certificate back in even when it's removed. This was deliberate. Dell decided that they were going to shove this certificate down the throat of everyone using their machines. The exact reasons are not relevant to people who have now had their security compromised.
If Dell can do this, anyone can, and they probably will if they haven't already done so. The direct consequence is that all preinstalled vendor Windows setups are now not trustworthy; they must be presumed to come from a hostile party, one that has actively compromised your security. If you can legally reinstall from known good Microsoft install media, you should do that. If you can't, well, you're screwed. And by that I mean that we're all screwed, because without trust in our hardware vendors we have nothing.
Given that Dell was willing to do this to business desktops, I expect that sooner or later someone will find similar vendor malware on preinstalled Windows images on server hardware (if they haven't already). Of course, IPMIs on server hardware are already an area of serious concern (and often security issues all on their own), even before vendors decide to start equipping them with features to 'manage' the host OS for you in the same way that the Dell startup program puts Dell's terrible certificate back even if you remove it.
(Don't assume that you're immune on servers just because you're running Linux instead of Windows. I look forward to the grim meathook future (tm jwz) where server vendors decide to auto-insert their binary kernel modules on boot to be helpful.)
Perhaps my gloomy cloud world future without generic stock servers is not so gloomy after all; if we can't trust generic stock servers anyways, their loss is clearly less significant. Smaller OEMs are probably much less likely to do things like this (for multiple reasons).