...when I rotate a "landscape image" and make it a "portrait"...
How are you doing this, exactly?
You need to rotate your entire image document.
Try this: Choose Image - Image Rotation - 90 Degrees Counterclockwise (or the appropriate choice). What do you see?
I've tried that and the image is still "cropped". I've also made the image a layer, made the image canvas larger, then tried to rotate the image as a transform, with the dimensions locked. It also crops when I rotate it that way
Can you please do screen grabs before and after, save them as JPEGs, and attach them to a post here?
You don't just need to zoom out, do you? Use the Zoom Tool to change how much of the image you can see. The Control 0 key combination will make it all fit.
I believe I have determined what was happening by thinking about my question after I posted it. As the "cropping" was system wide, I realized the problem had to to do with the system and not Adobe. So I looked at the aspect ratio of the monitor by looking at the vendor's specs for it on line. The problem went away when I changed the graphic card aspect ratio to the correct ratio for the monitor
Thank you Mr. Carboni for your input. I found that my graphic card was set at the wrong aspect ratio for the monitor.