Windows 98: The Daily Test Cycle
This is Microsoft's other video showing the testing process of their other flagship product, Windows 98 of the Chicago lineage. The video makes it unambiguous that plenty of testing was done on Windows 98 to ensure compatibility with a wide range of hardware and software (except those Oak Technology VGA cards; support for them was dropped because they suck horribly). The original release of Windows 98 certainly did deliver on that compatibility with both Windows 3.1x and Windows 95 programs in my personal experience, but even so, the rigorous testing didn't seem to stop the launch from being disastrous. Depending on the hardware and drivers being used, Windows 98 could get by all fine, but in other configurations I've used, it would either crash on the first or second boot or not even be able to complete installation. At this rate, maybe it should've just been Windows 99, because the advice you get from most everyone these days is "just use 98SE".