When I got my laptop it had Win 8.1 installed. Showed only 3.68GB RAM usable but when I installed all GPU drivers also for Nvidia I got it resolved.. Showed 4GB.. Then I upgraded to WIN 10, no probs... And now I got the same problem again.. I understand that I have fixed 64MB to intel gpu, however back then it showed me 4GB, now it shows 4GB (3.89GB usable).. Please help me get this resolved.