Switched from windows 10 to windows 8.1 pro; missing drivers

[warmachine8]

As the title describes, I'm missing drivers from the swap. The drivers I'm missing are as follows:

Network Controller
PCI Data Acquisition and Signal Processing Controller
PCI Memory Controller
SM Bus Controller

How do I get these device drivers? The machine that needs them is my Lenovo Legion Y520-15IKBN if that matters.

 

[Darkbreeze]

That system does not support Windows 8.1. The hardware in that system is too new, and while you can TRY the Windows 10 drivers in 8.1, often they will not work. Lenovo officially does not offer drivers for ANY operating system version older than Windows 10 for that machine.

Sometimes when you ask "how do I do this", the answer is simply, "you don't".