Created attachment 735282 [details]
Memtest86 screenshot
To rule out the possibility of a hardware issue, I ran two Memtest86 5.01
sessions from a Clonezilla bootable CD. The first was in the day for 5 hours,
the second was during the night for over 10 hours: The program only registered
3 passes in total, but it did not find any errors. I'll attach a picture just
in case any useful information is printed there.