Ok so here it is.For example,the pc works perfectly for like 2-3 months and then for a week this happens like 6-7 times or so and then after some time it works normal again.Heres the prob example:I was browsing steam groups page,checking for news and steam suddenly froze.As soon as that happened my HDD led started glowing constantly.Then i open task manager,it freezes too(the other parts of PC work).Then i open start menu to try and restart,it freezes too.So eventually the whole pc freezes(HDD led is still glowing constantly).Then i reboot,and it usually fires up without probs and works.And as i said,it works fine for months and then suddenly happens,then it goes away and after some time appears again etc...