Changing motherboard and CPU without having to reinstall everything on the OS hard drive

Yes, this is technically possible, but doesnt always work. As the article states, uninstall antivirus and your display drivers. I would, if Windows doesnt already have the drivers, install the drivers for the disk controller. Assuming there is no other hardware preventing Windows from booting, it should work.

That being said, I always prefer a clean install and update Windows. This allows me to have a baseline install, then take an image of the machine absolutely clean of extra software. Then, I install the absolute must have software I have on every machine and take another image. This way I can always go back to either working image. Just my preference.