Recently I noticed at work that the background in Windows Photo Viewer was slightly yellow. After some googling I found out that it has to do with my Samsung monitor and a driver that was “conflicting with Windows’ Color Management System”
If you have the same problems, just follow the instructions on http://answers.microsoft.com/en-us/windows/forum/windows_7-windows_programs/windows-photo-viewer-background-colour-not-white/eef22f9f-8e9d-4cb9-b842-139bda7b03ed and hopefully the background in Windows Photo Viewer will be displayed correctly again