Hey, guys!
Sorry for the delay again. I had some issues during the weekend one more time...
Anyway, I also have some good news! Some time ago I sent my new computer (the one that wasn't working properly) to the authorized technical assistance. Since it was in SΓ£o Paulo, far away from my town, the computer took some time to get there.
But yesterday I finally received an answer, and they told me they will send me a new computer! They said that despite the fact that I had opened the computer case to put a second HD there, the problem hadn't been caused by that, and that PC would present issues sooner or later.
I really appreciated their honesty, and I'm sooo happy! I hope to be able to make prettier renders for my future stories now!
:-)