Windows 1.01, 1985
Microsoft's first attempt at a graphical user interface for MS-DOS was, in a word, dreadful. It was ugly, it shipped two years late and even then didn't work well. And besides, there wasn't anything that would run on it anyway. Windows applications really didn't get going until Windows 2.03 showed up two years later.
Adding insult to injury, by the time Windows 1 was launched, the Mac was already offering the far superior System 2.1. That Mac OS included AppleTalk networking, PostScript printing with the first LaserWriter printer and the first sophisticated PC-based file system: Hierarchical File System. There was no comparison.
MS-DOS 4.0, 1988
It's not like Microsoft was still spending much time in 1988 getting MS-DOS right. The earlier versions of the operating system really weren't bad for their day; MS-DOS 3.3 was actually quite good.
But then along came MS-DOS 4.0. Oh, it was horrid. Programs broke on it as regularly as clockwork. You'd be in the middle of a task, and your program would just freeze up completely. Nothing this bad was seen again until Windows' Blue Screen of Death.
To save their sanity, PC users either dropped back to MS-DOS 3.3 or moved to Digital Research's DR-DOS 3.41 as fast they could. Although the DR-DOS version numbers had been mimicking those of MS-DOS to show similar functionality, Digital Research chose to name its new 1989 version DR-DOS 5.0 to prevent anyone from thinking that it had any connection with MS-DOS 4.0.
SCO Open Desktop, 1989
On the plus side, it was the first 32-bit Unix with a graphical interface. On the minus side, its nickname was Open Deathtrap.
Open Desktop would, could, and did blow up in some of the most entertaining ways I'd ever seen. I had editors freeze up and compilers bring the entire system to a core dump -- and there were times I never knew which, if any, window I was actually working in.
Strangely, I was actually able to get productive work done on Open Desktop. I suspect I might have been the only one who managed it.
Want to know a really bad idea for an operating system? Write it in a language that's as slow as mud -- as Java was in 1996. Nevertheless, Sun, with some help from IBM, tried it anyway. JavaOS was designed to run on network computers and embedded systems.
How did it go? Well, let me put it to you this way: Have you ever heard of it? There are many well-known embedded systems: Qnx, VxWorks, Symbian, Windows CE and the list goes on. But even in embedded operating system circles, few people have ever heard of JavaOS.
Although several companies licensed it, the only product I know of that used it commercially was Sun's own long-forgotten JavaStation network computer. By 2006, Sun had dumped it into the "legacy system" junkyard, and that was the end of the Java-based operating system.