hmm i've already changed the position of the ram's , it's like this, there is position A and B, and RAM 1 and RAM 2
RAM 1 = 2GB
RAM 2 = 4GB
I placed the RAM 1 on A and RAM 2 on B, the bsod starts exactly when windows login. i placed RAM 1 on B and RAM 2 on A, the bsod starts randomly, between 8 hours or 4 hours laptop usage time. it is like that