Is that even possible any more? (That said, "operate" isn't a boolean, it's a continuum between perfect service and none, with various levels of degraded service between, even if you mean "operate" in the sense of "perform a surgical operation" rather than "any treatment or care of any kind").
All medical notes being printed in hard-copy could be done, that's the relatively easy part. But there's a lot of stuff which is inherently IT these days, gene sequencing, CT scans, etc., there's a lot that computers add which humans can't do ourselves — even video consultation (let alone remote surgery) with experts from a different hospital, which does involve a human, that human can't be everywhere at once: https://en.wikipedia.org/wiki/Telehealth
> Nothing critical / life-or-death / personal injury should rely on Windows / IT systems.
If you think that's bad, you may want to ensure you're seated before reading this about the UK nuclear deterrent: https://en.wikipedia.org/wiki/Submarine_Command_System
If someone is injured or dies because the hospital has inadequate backup processes in the event of a Windows outage, some or maybe all liability for negligence falls on those who designed the hospital that way, not the IT supplier who didn't agree to it.
The tool isn't fit for purpose