What is the least successful OS ever sold?

[Iggy]

How about OS-9 for the Coco 3?

WHAT? Not only was that reasonably successful, but there is still a open source version of it available for download called NitrOS.
I don't think you want to use an OS that sold tens of thousands of copies as an example of an unsuccessful OS.

By the way, I can point to groups that are still using and developing under this.

Also, come to think of it, just a couple months ago I saw an announcement that Radisys (which bought OS9 from Microware) was releasing an update for 68K version for OS9.

Further OS9 is still available for many platforms. The X86 version is very popular in the process control market.

You sir, have no clue what you are talking about.

[Iggy]

I have thought, and always will think, that Windows ME is the worst, nay atrocious, OS I have ever had the misfortune to use. It was buggy, slow, leaked memory, blue-screened, died more times than super meat boy and ate resources like it was going out of fashion.

Personally, I had no more problems with Me then I did with 98. Most of the problems you list are present in both OS'.
Me had more device drivers on the install CD and virtually all this CD's content was loaded on to the computer's hard drive. That meant that when you installed new hardware you didn't have to put the OS CD into your computer.

With all the vitriolic comments, you'd think ME was a new operating system. In reality it was little more than a slightly enhanced 98.