thanks @ptrblck. Thank you for your help. What I don’t understand is this. I want to use pre-trained weights and a proven model. When I say .pretrained=True, it downloads the pth file and these weights. I want to use them. but don’t I need to freeze the parameters? what happens if i don’t freeze the parameters? I don’t want to train from scratch I want to use a certain model and weights and add a few final layers to the model. i just want to train the layers i add