Open Source and Free Software

Yes, Microsoft were rather shackled by having to retrofit security into an old operating system designed for single user mode and before the internet, and without sacrificing compatibility. All that was redesigned from scratch with NT by Dave Cutler and his team.

I was never very happy with the filesystem security model with its ACLs, SACLs, DACLs and what have you, which I thought rather over-elaborate compared to the simpler but cleaner *NIX implementation which would cover 99% of what you'd need and was much easier to use and work with.

Of course, if you have physical access to a computer, only a highly encrypted file system will keep you from cracking it rather easily. Relatively few would have been willing to sacrifice the processor cycles that would have taken to maintain, though. At least in those days (I left shortly before Windows 2K came out).