Not the obvious solution, but I have had no errors since I installed the SATA AHCI driver from the "RST and AHCI Driver and GUI" file package. My computer is also running smoother than previously. So I guess that everything is well.
People with the same issue can search for the file package at Intel Downloads by using the words "RST and AHCI Driver and GUI". I used Windows Device Manager for installing the driver. Both x86 and x64 drivers are in the folder called Drivers.
Case solved.
Laurus