@Watchman, one of the reasons Macs performs very well is because Apple tightly controls the hardware and software that runs on their machines so they provide excellent support for the devices supplied. Try installing O.S X on a dell / hp box for instance and tell me if you will have  better experiences than the ones mentioned above. Windows / Linux / other *NIXes on the other hand try to run on as many platforms as possible, albeit not as smoothly in some cases. At least give them some credit for that.

Even if you get access to the sources of Seven from Microsoft, I doubt you will be able to build and / or compile it. I do not think Visual studio suffices for the task at all, there must be some highly specialized in-house tools for doing that. At the same time if you get past that, wrapping your head around the program might be another nightmare. I guess there must be thousands of developers working on the kernel alone which must be on or near ten of millions of lines or code.

Anyway, I bet there must be a solution to your issues. Either get a better anti-virus or other drivers to your device.

Martin.