My PC starts just by clicking left mouse button

[ne4a]

Completely shutdown pc starts when left mouse clicked(solutions)

 

[Colif]

Well, Windows 10 isn't actually shutdown when you turn it off. That is, unless you have Fast Startup turned off. It uses hybrid hibernate and saves a copy of kernel and loaded drivers into the hiberfil.sys on shutdown meaning PC bounces back to life on start up since its much faster to load just 1 thing than to reload all your software again: https://www.tenforums.com/tutorials/4189-turn-off-fast-startup-windows-10-a.html

What mouse is it? Does it have its own software or just use default drivers?