Go under "Internet Options" to see what is set as the default program to open images for viewing. For some reason, those get changed the most in IE. I use MS Picture It to view all images and I have from time-to-time make sure it is the set program to use. However, a better idea, is to use Mozella Fixfox as your browser. It doesn't have all the issues that IE has and seems to be more efficient. One thing for sure, the hackers have not been after it as much as IE.
Hope this helps...