Hardware differences??
"mixture between LINUX and UNIX" Impossible! GPL violations right there. I assume you mean Gnu or something else entirely but the Linux kernel has never been mixed with Unix code because that would enact the death clause and the result would be still born.
"As for Windows security: If you have 99% of the world's hackers focusing on you, problems will be found. So what?"
Most of the real crackers are focusing on Linux and Mac OS X; criminals are going after windows because of the money. crackers want prestige and what's better than showing off that you've made the worlds first virulent linux or mac virus?
"If Microsoft could release their own PC with all their own hardware and their own drivers it would be a completely different matter."
Not really, windows exploitations have always been in the apps, networking and various other none hardware driver code; some are driver related but not nearly enough for your comment to make sense.
"The simple fact that Windows will run quite reliably on virtually any Intel compatable hardware, with third party drivers is miraculous to say the least."
Not really, I mean ok so it's windows but linux runs on even more hardware, it runs of x86, PPCs, Riscs, Z86s for crying out loud. windows has a rather limiting hardware scope in comparison, just look at the Firewire stack in windows, ew.