Have you seen up to day 4 and 5? In these days Casey is changing pixels and putting them on window.
The approach he takes is one where he allocated memory for holding bitmap, changes values that represents pixels. And then blits whole memory to screen. This is one of the faster ways how to put pixels on window.
Another option for drawing in Windows is to use
GDI functions. They provide drawing pixels, lines, etc.. each with its own function. Drawing will happen into internal buffer, so no blitting required. This will be a bit slower way because of function call overhead. There's also
GDI+ API with a bit more advanced functionality, and more features like antialised primitives.
Unfortunately creating window and managing it in Windows will require some boilerplate code which you cannot really avoid (unless you use somebodies library which will do that for you). The good news is that once you do it, you can forget about it and just focus on your pixels.
As for libraries that will do all the window setup for you and allow plot pixels in software to screen out [url=
https://github.com/emoon/minifb
]MiniFB[/url] or
PixelToaster. They both will have similar code as in Handmade Hero from day 4/5. Well PixelToaster is a bit more advanced with float pixel format (possible by using d3d9).