I have a DELL Inspiron 15R Laptop since 6 months. When I was working on my laptop, suddenly all the programs froze and wouldn't react. For like 20 minutes I couldn't do anything on it, just swiping between the applications that were open. After that I just saw my background and an error. I clicked OK and since then I only saw a background. I restarted the laptop after a few minutes by pushing the power button. It started to make some strange noises and said I needed to reboot my system. I got a black screen with some text, that for me is incomprehensible. The last sentence is: "No boot device found. Press any key to reboot the machine." When I do that, it just restarts and I get the same screen over and over again.

What can I do about it?