a swiss cheese operating system that was not built from the ground up with multiple users and the access from the outside in mind
Exactly.
No matter which way you slice it or dice it, Windows is still Dos 1.1 underneath. With a vector table at 0:0000
I’ve never examined the vector table on an x86 machine running under Windows and compared it to one running barebones Dos, but I am willing to bet there are a few interrupts that Windows doesn’t front-end.
And even if they do protect the hardware interrupts, Windows wanted to make itself a one size fits all OS where stuff like Java and Flash can come along and do spiffy things. Spiffy and sometimes very malicious.
As a systems guy, I would never let ANYBODY tweak what happens when the boot process happens. I would NEVER let anybody mod anything on the system packs! (mainframes rule!!!)
Microsoft is not the only OS which allows PDFs, JPG, or web payloads to execute code without user approval.
At least according to company announcements.