Aveces algo pequeño puede significar mucho mas que algo que pesa mucho mas me parece absurdo eso de escoger por el peso pero bueno se respeta el gusto de los que han experimentado y sacan esa teoria :troll:

Okay, it seems to be fixed, although in a somewhat strange way:

I downloaded the file that W7 offered me, installed it, and it was a utility to control a "refresh mode" of CPUs that comes with some Asus motherboards.

Mine doesn't have it so the program, when I started it, told me it was incompatible. I uninstalled it and ¡Tachín! the message is gone.

I have no idea why it came up, but the alert message is gone, so I consider it fixed…

Thanks a lot to everyone for the advice!

Okay, I already know what it was: the power supply.

It wasn't completely broken yet, but it was on its last legs... I went to a trusted store and they recommended putting a more powerful one in (520, if I remember correctly), I changed it and... ta-da! the problem disappeared, both the electrical noises and the temperature spikes and slowdowns... my PC is working properly again!

However, I got myself a UPS, just in case... I don't trust voltage spikes. And I'm also thinking about putting a cooling system on the CPU and the graphics card, which are the parts that suffer the most in my computer... I'll look into it when I have some money.

Many thanks to everyone for the help, suggestions and advice... now, if any of the administrators can close the thread, we can consider it solved, even though in the end it had nothing to do with the graphics card...

That's it: Thank you very much!