Windows XP was the last client version of Windows to include the Pinball game that had been part of Windows since Windows 95.
One of the things I did in Windows XP was port several millions of lines of code from 32-bit to 64-bit […] But one of the programs that ran into trouble was Pinball. The 64-bit version of Pinball had a pretty nasty bug where the ball would simply pass through other objects like a ghost.
Two of us tried to debug the program to figure out what was going on, but given that this was code written several years earlier by an outside company, and that nobody at Microsoft ever understood how the code worked (much less still understood it), and that most of the code was completely uncommented, we simply couldn’t figure out why the collision detector was not working.
We had several million lines of code still to port, so we couldn’t afford to spend days studying the code […] We just made the executive decision right there to drop Pinball from the product.
[Why was Pinball removed from Windows Vista? sur OldNewThing]
Microsoft qui s’explique sur une de ses décisions, même des années après; le changement est en marche.