Most likely cause would be a missing ICC profile in the photo file. If you open a photo in Photoshop and then open that same photo in Windows photo viewer and place them side by side on the screen they should appear identical.
I don´t think it is a missing ICC Profile in the image because when i download an image from the web its the same problem. I will attach a screenshot that shows the same image viewed in Windows Picture Viewer and Photoshop.
I have read that the issue may be that Windows Picture Viewer is not Color managed, do you know anything about that?
Windows Picture Viewer is color managed in that it responds correctly to embedded ICC profiles in images.
Another guess would be a large enough discrepancy between your monitor's calibrated state and it's profile so that you're seeing Photoshop processing the new monitor profile, but I would expect Photo Viewer to do the same.
I think that's it. It's your new monitor profile. Photoshop is using that new profile and Windows Photo Viewer is not using the new profile. You're then seeing the discrepancy between your monitor's physically calibrated state and the i1 Display profile.