I'm currently inside a hospital data center and I can tell you that windows is behind the scenes of a lot of the systems we use. Everyone in "the know" thinks it sucks that the majority of the problems we encounter is because of borked hardware configurations in appliance machines or Windows servers. We are on mainframe (as of today, it's still the only way to get everyone's critical data to almost a dozen moajor sites at once with 99.9 uptime and I don't see us abandoning it anytime soon) and there is a god-damned Windows server that is only used to encode EDI transactions to the JES2 spooler that always crashes, causing the spool to fill up, endangering the entire system. It's a very serious problem as the only solution to it once JES is full is to IPL the system.
The server in question doesn't even show an error message. Well, sometimes it does, sometimes it doesn't. you can stop and start the services all you like, but you're just wasting time as the JES2 spool gets bigger. The only solution is to reboot the Windows Server. It is redundantly mirrored, but we any of you with any sense will know that this does not make the situation any less frightening. The mirror is bound to be subject to the exact same problem, since it's software-related, which would put you back at square 1 in the event of a fail-over.
Don't even get me started about malware. Of course, all the workstations throughout the system are Windows systems. Those should not matter in case of a power outage or system-wide failure because we have downtime procedures in place, but let's face it, we'd be majorly crippled if we were to ever loose our entire network and it would likely impair our ability to serve customers. Although it shouldn't. So far we've been lucky.