Well, except of course the entity that gave you the hardware. And the entity that preinstalled and/or gave you the OS image. And that that entity wasn't fooled into including malicious code in some roundabout way.
like it or not, there's currently no real way to use any significant amount of computing power without trusting someone. And usually several hundreds/thousands of someones.
The best you can hope for is to focus the trust into a small number of entities that have it in their own self interest to prove worthy of that trust.