Unless you have a separate security manager for that system, the best thing for you to do is to be SURE that you keep your system patched and up to date. Yes, Microsoft will publish some clinkers and you might need to back out a patch now and then. However, when I was a system admin for the U.S. Navy, our security classes included a statistic that the #1 cause of system security issues was the failure of the admin to keep the system patches up to date. This will mean determining a schedule on which to do the patches, worked out with management to pick the optimum time. For me, it was twice a month I would come in late and work late (after the rest of the staff had left for the day.) The good news is that Windows patching is pretty much automatic. You will, however, have to learn how to prevent the automatic Windows patching that WinServers like to follow. Because if you don't control that, you will have down time whether you wanted it or not.
If you get pushback from management about scheduled down time, tell them unconditionally NO, that if you cannot protect the data with regular security actions such as patching, you cannot protect the data at all. If they tell you you can't have a regular period of patching, make sure you get that in writing with witnesses and let them know that an "I told you so" is ready and waiting because it WILL be needed.
If they ask where you got this idea, show them this post. My credentials are expired now, but when I was active, I had CompTIA Security+ and HP Operating System credentials. I taught computer security for the Navy Enterprise Data Center, New Orleans for a couple of years before they decided to go with professional off-site courses and national certification. I was the system admin and security admin for the U.S. Navy Reserve server that mobilized reservists in times of war - such as during Desert Shield and Desert Storm. I had 28 1/2 years of experience in keeping that system up and available. Outside of the scheduled maintenance times, I had a 99.79% availability average. As to the other .21%, even the best hardware fails now and then.