My take on this is

  1. This is a 4 week old PC, so unlikely to have accumulated a significant amount of data, since it is new, you can just copy the data back from wherever
  2. This is not anything with Sony, you speaking with them has misled you into thinking it is a their problem, they make hardware, so you need to blame the software
  3. Perform a factory reset on the computer, the Sony team will tell you how to do this, it is the best option, otherwise you will start building a house on top of sand and complain that you have suffered death by many thousands of cuts, and again because this is a new PC, it shouldn't be that much hassle to just reinstall everything
  4. after the factory reset, ensure you have a separate partition e.g. c:\ for windows and d:\ for data, so if things do go wrong, all you need to do is re-install your programs

In an ideal world everything would always work, and I have issues with Apple and Android software as well as Windows