Is it stalling when the 4 colored blocks appear? I had this same problem and it was very annoying. Everything I tried would not work until one day I removed the video card and tried to start it again. It failed, so I shut it down and left it for about 2 weeks. Turned it on and it worked. About three days into using it. It started to happen again. Went through the whole procedure again and it failed. I used a different hard drive with a fresh Win 7 OS and it still did it. My build at the time was and AMD A10-5800K. I recently purchased a Intel chip and mobo and have never experienced that issue again. Many forum sttrings about the AMD chips doing this. I don't know if that is speculation or not.