If you transfer with your smartphone photos and pictures to the Windows PC via USB cable or via e-mail, then it can happen that you will not be able to rotate an image with a image-viewer such as Windows Photo Viewer.
The reason for this is usually the following: Your smartphone dubbed the images with a write protection. If Windows detects images with write protection, then this cannot be rotated. That is why you must now remove the write protection for the pictures which you would like to rotate.
This is very easy as follows:
1. Navigate with a right click on the image and then choose “Properties” from the pop-up menu
2. Open the properties now. Change on the "General" tab
3. In the section "attributes" you must now remove the option "Read-only", by deleting the hook. Done!
It is now possible to rotate the image, for example with the Windows Picture and Fax Viewer.