Sorry for late answer.
I think there was a problem with printer driver: "Samsung Universal Print Driver 2 PCL6". I replace it by ""Samsung Universal Print Driver 2 v.2.50.06.00" and now I test computer all day and its ok. I think the problem is solved. Thank you for your help.
Hello,
Computer runs the longest for a few hours, the shortest a few minutes.
There is no rule whether you work or not.
There is no message.
I do not know how to deal with this problem.
I enclose reports and memory test.
Please help.