Hi while working my comp I get those clicking noises and sounds like something is spinning followed by my comp developing a blue screen then a black screen telling me it can't find the operating system and to put in my OS disc this has occurred a few times I have dis mantled the whole lot checked it and re-assembled . It turns out when I give the tower a sharp knock the noise stops and it acts like nothing has happened > *****! could I be right thinking I have a bad electric connection ? It's a gigabyte m/board with on-board graphics i5-2400 CPU @3.10 GHz 311 GHz only six months old . If anyone can tell me what the problem might be I would appreciate It . Regard Drecked PS: I have a hard drive loaded with widows 7 I use some time and the same happens with that drive because I first thought that the hard drive was in the process of carking It., Incidentally happens about every two to three weeks ! Looking forward to a cure !