Aside from other stuff others already mentioned, I would also want to add:
Windows Vista and onwards, MS, while claiming it was for technical and stability reasons, nixed a lot of features that were annoying to movie studios, basically they changed how driver stack worked in a way to make DRM easier and make harder to pirate movies.
But as consequence of that, a lot of cool stuff outright stopped working:
* Some interesting video modes
* Some obscure ways to output data
* And the one that annoyed me the most: Soundcards became useless.
Before that, Soundcards could do a LOT, they could have their own processor and do a lot of fancy stuff, most famously they could do "3D Audio", and it was super cool, Thief for example is a game that uses it well, it would use its own processor to do same thing GPUs do for graphics, and do it for audio, it would even raytrace sound (ie: suppose a character is on the other side of the wall, but there is a door on that wall, the card would calculate the sound of that character footsteps reflecting on the walls and reach you, then if you were using headphone or 4+ speakers it would make you hear the sound coming from the reflections, thus a person with good hearing could deduce where an enemy was, on the other side of a wall).
That stunt basically killed off the soundcard market, people then were making cooler and cooler cards, after that the cards became little more than just output ports soldered on a tiny board.
Sound Cards pre-vista:
https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Cr...
Sound Cards post-vista:
https://http2.mlstatic.com/D_NQ_NP_768672-MLB41729093507_052...