So you're refusing to have a basic update installed? Let me guess, you're going to complain and say Windows is insecure because you got WannaCry'd because you didn't update your system and blame it on MS instead?
It’s unlikely to get WannaCry unless the PC is connected to internet or LAN.
The software we’re offering doesn’t require to be online. It normally works unattended for hours, controlling some specialized industrial hardware. Not unlike embedded software. For this particular use case, being offline has it’s upsides: no downloads, no updates, no reboots.
The users who discovered that bug (initially I did include these CRT merge modules in my installer, as recommended by MS) didn’t even send us a screenshot. Instead, they took a photo of their PC’s screens with the error message, and sent us that. Then I was able to reproduce on an offline Win7 VmWare machine, and deliver a fixed version with statically linked CRT, which BTW worked OK even on a vanilla Windows 7 sp0 from 2009.
Personally, I would recommend updating Windows instead, and I do update the PCs I own. But I can, and do, support running my software on a never updated system.
(you = whoever "doesn't care" about updates)