Ya, forced windows updates are a pain. (Pi hole is certainly a good solution, until you need to VPN out to a network that is less discerning...) - That said, the security update that microsoft pushed out this week is really rather an important one, so assuming that you can find your photo's, perhaps it's for the best that your computer decided that it desperatly needed to update.
What do you mean by gone. I'm guessing you are moving the files off your SD card via a program (as an Import), rather than a direct file copy to your hard drive. - Do you know where that program stores your imported Nikon files?
A windows update should never cause you to loose your actual image files, but I can perhaps see your photo program forgetting that it imported some files just before the windows update, espectially if that update forced the program to exit when rebooting. If that's the case, it should be fairly simply to re-import them from whereever the program deposited your photos on the hard drive.
