Unable to scale an image in Photoshop

I have noticed already a few months ago that the photoshop program on my computer does not want to scale an image when clicking on the image. I click on it and there is no marking on the outside of the image. Normally you click on it and the program forms a thin line on the outside of the image that you can use to scale the image. How do I solve this problem? I have already deleted the program of my computer and re-instald it.