The quest to put Windows 95 on seemingly everything just achieved one of its biggest -- or rather, smallest -- feats to date. Nick Lee managed to get Microsoft's classic operating system running on an Apple Watch by modfiying a WatchKit app to load his own code (in this case, the Bochs x86 emulator) instead of Apple's usual foundations. The interface is incredibly miniscule, of course, but it works. While you don't have a true mouse pointer, you can use the touchscreen to navigate the Start menu and open apps.
Just don't plan to relive the halcyon days of MSN and Full Tilt Pinball. It takes an hour for Windows to load, and calling the interface response time "glacial" might be generous. Lee even rigged a motor to keep touching the crown so that the watch screen wouldn't shut off after several seconds. If you're determined to recreate this Frankenstein's-monster of a Windows port, though, the developer has posted what code he can distribute on GitHub so that you can give it a shot yourself.