http://www.tomshardware.com/faq/id-1653253/fix-driver-power-state-failure-windows.html and many other posts exist but you may be asking for a step by step for your specific laptop.

Frankly I'd not do this. I'd move it up to Windows 10 and see if that takes care of it.
If you need a good start menu, install Classic Shell.

I'm encountering a lot of folk demanding step by step but with some million different PCs I can only guide. That is, I would be looking at Tosh's site for the model in question for the motherboard chipset driver package. That is Greek to many.

I'd try the Windows 10 exit.