Tech support please!

Yeah they're one separate harddrives.

Both were installed on the laptop, using a bootable USB.

I'm SO OP, SOMEBODY PLEASE NERF ME!!!!!

I am surprised you would even try that. Even if it boots won't it go "OH MY GOD SO MANY UNKNOWN DEVICES, MY DRIVERS DONT MATCH"?

nowadays drivers and windows (especially nvidia) are quite flexible

I've swapped graphic cards and CPU in systems more times then i can count.

audio just won't work until you uninstall old driver and new one.

it's totally doable.

No good reason to try it and as we see here it can fail Building a new system is a good reason to cleanup the old dirt.
Also swapping a graphics card sure is easy. But the mainboard? From laptop to real computer? yeah....

you've got a point.

I'd done motherboard from PC to PC but never from laptop to PC, so indeed there is good call for foretelling it won't work.

unless you're running linux

Apparently linux doesn't give a ****, huehuehuehue.

So, you pulled your Win 10 installation from your laptop and are trying to put it on a desktop workout reinstalling?

That'd be your issue. Windows can sometimes get by with the same chipset but since it won't be the same, and the hardware is probably quite different, it doesn't load things properly for the BIOS to recognize it. Windows sets up things for one set of base hardware (usually only the motherboard, switching CPUs isn't necessarily a problem) and when that radically changes, is not set up for that.

Linux is overly flexible and so that's why it works so well Also, I think the Linux kernel stores all of the drivers it needs unlike the windows kernal which has to aquire then during and after install.