I thought I should mention this here.
This is a problem I had back when I was still using the beta and it carried over to the release and current version of 7.
I found a solution tonight and I wanted to share that solution.
The problem is that the default viewer for .gif is internet explorer. I want to be able to double click a .gif and have it preview with Photo Viewer like everything else. There are several problems with that happening. I give more insight in my tutorial on how to fix this issue here:
http://www.sevenforums.com/tutorials...f-preview.html