So I searched on Google and I did the test, "Memtest + 86"
At first, I did this test with the bars that I had, no errors appeared.
I have removed and replaced by the 2 above Kingston.
The verdict came on, there has been full of errors directly !!!
Obviously the 30 day return period is expired, I lost 57,80 ...
I can only recommend to the Test at reception of the order, it will avoid surprises ... and especially blue screens ...