Windows 95 and its immediate successors had a lot of problems regarding stability, memory usage, performance in certain cases, etc. That and the comparison with the NT OS line is a separate discussion however. What is important about Windows 95 was the design of the GUI. At the time, it was a huge leap forward in desktop computing.
Even though I jumped on the Mac OS X bandwagon from the very first moment in 2001 and was happy to leave the Windows world behind, the fact remains that for a few years time in the mid 90s, Microsoft showed a strong ability to design GUIs that were easy to use, relatively consistent, and flexible enough to suit a large array of first and third-party application designs. It's a shame that, IMHO, Windows XP took things in a highly negative direction after that, and Microsoft never fully recovered. With the possible exception of Windows 7, every OS release since XP has been a mishmash of competing ideas and confusing discrepancies, and macOS has continually outpaced Windows in usability.
I still hold out hope that there's a solid future for Windows when it comes to UX/UI design, if only because I want macOS to have real competition on that front.
Microsoft in the 1990s had a strong penchant for striking the right balance between power users and the average user. Their products remained full-featured but most of things you didn't use day-to-day were quietly tucked away in areas only power users would care about. There wasn't any real notion of compromising usability for simplicity. If you wanted to customise finer aspects of Windows 95, all it would take is a registry entry. If you wanted to use an advanced feature in Office, all it would take is a deep trip inside the menu bar. If you didn't want to do either of these things, they stayed out of your way.
Apple later pioneered the notion of making products so radically simplistic, they sacrificed functionality on the pretense that power users wouldn't be bothered by the absence of features. There was almost no customisation. You got what you bought and liked it. Finder, the worst file manager I've ever used as a developer, endlessly gets in your way in the name of not letting grandma mess up her system.
Microsoft later badly copied Apple, and the result are horrid and unusable "Metro" style applications.
The Task Bar and Start Menu metaphors have held up well. At the time on the Mac, it was harder to see an overview of running Applications and windows at a glance.
True. I didn't have much experience with the Mac back in the Mac OS classic era, but that was one thing I found very annoying coming from the Windows side. While it took a while to get the Dock right in OS X, it was a big improvement over the previous Mac UI.
I disagree that OSX completely beats Windows GUI in all areas. I find Windows' window manager, Explorer and taskbar more usable and capable than the Mac equivalents. Not to mention everything is more configurable, after many years using OSX I still get confused with the unchangeable, low contrast, light-grey on top of light-grey, window theme where you can't tell which window has focus. Also miss on OSX how you can tab over to everything in Windows without having to use your mouse.
Even though I jumped on the Mac OS X bandwagon from the very first moment in 2001 and was happy to leave the Windows world behind, the fact remains that for a few years time in the mid 90s, Microsoft showed a strong ability to design GUIs that were easy to use, relatively consistent, and flexible enough to suit a large array of first and third-party application designs. It's a shame that, IMHO, Windows XP took things in a highly negative direction after that, and Microsoft never fully recovered. With the possible exception of Windows 7, every OS release since XP has been a mishmash of competing ideas and confusing discrepancies, and macOS has continually outpaced Windows in usability.
I still hold out hope that there's a solid future for Windows when it comes to UX/UI design, if only because I want macOS to have real competition on that front.