lol You really underestimate your english. I've read people that are actually terrible, you however aren't doing bad at all.
As for your problem, I'm going to have to make a guess (since I'm not there) and say you should look at your PSU. If it's not the PSU then things get kinda sketchy, it's going to be a main component and we can't easily eliminate those without a BSOD (or specific error codes of any kind). So that will have to be trial/error.
Firstly, thank you.
A-and for the PSU "test". How can I do this? I mean how can I understand if it's working alright or it isn't?