I have a serious problem here, my desktop suddenly shutdown. I was testing my HDD and I found that it has some bad sectors, so I bought a new one: WD GREEN 500gb. After that everything went right, however this two days, while working or playing games on my desktop, it turns off on it’s own. I even installed other operating systems, and while installing lubuntu 15 it shutdown during the installation. I'm sure there is something wrong with the hardware but I don't know what piece is damaged.

Thanks in advance.

I have a serious problem here, my desktop suddenly shutdown. I was testing my HDD and I found that it has some bad sectors, so I bought a new one: WD GREEN 500gb. After that everything went right, however this two days, while working or playing games on my desktop, it turns off on it’s own. I even installed other operating systems, and while installing lubuntu 15 it shutdown during the installation. I'm sure there is something wrong with the hardware but I don't know what piece is damaged.

What steps can I use to diagnose the problem?