Why sometimes I am not able to select the picture to import from camera to PC?

When Windows detects your newest pictures. It doesn't import duplicate versions of older pictures that you've already copied to your computer from your Samsung camera, it's now easy to import your pictures to the Pictures folder in a single step.

In addition, we recommend that you review your imported pictures in Photo Gallery, where large previews make it easy to decide which newly imported pictures to delete from your computer.