so i have this HP probook 4520s, windows 7 x64,intel core i3 2.27 Ghz Quad, 4Gb RAM , amd radeon hd 4300/4500 2Gb graphics and a 768p screen. the problem here is unknown, im used to fatal crashes (blue screen) but that was usually about overclocked GPU/RAM or some indefinite error, yet they have been there for a long time so its not a big deal. the point is that today i got and fatal crash, which said , that a core stopped working, either it stopped, either it didnt respond, so it was the first time i have seen that error, also, before that, the i was watching a video and the PC froze and the sound kept like a *bzzzzzz* and at the blue screen, when dumping memory on disk, it froze. any reasons why it happend?