How do I stop automatically rotating vertical photos?

when i open vertical format photographs in Photoshop CS, it automatically rotates them, but then when viewed in other programmes (windows slide show as an example),they are not rotated...if i rotate them to look right in those programmes then they are wrong in photoshop...it is a bit annoying.

I would prefer to rotate the images manually.

any idea how to turn off this automatic rotate function for Photoshop CS?

The problem is that there's a tag in your image, embedded by the camera, telling software that reads it correctly to rotate the image when opening it. Photoshop respects this tag, other software does not.

I believe on my camera (canon s2) there's an option to turn off the tagging...