@sun >re-implementation of Windows over time to make it more secure
That has *not* been done.

They've sporadically rewritten a lot of it, except wrong, with some rusty plates installed over some of the holes in the swiss cheese.

One example of why it's so shit is because they've stopped using GNU make as the buildsystem and have gone with their own terrible buildsystem that likes to return just -1 if anything goes wrong.

The performance degradation is due to incompetence rather than a pact with manufacturers - the OS itself is designed to break itself after just a few years due to garbage in the registry etc, which makes people go and buy a new computer.

Manufacturers try to go with the slowest possible hardware to keep the profit margins up, considering that microsoft takes a huge chunk out of it, so they don't want the base version to be a bloated pig.