DCIM won't fully load when I plug in to my computer.

Hello,

I am trying to get a bunch of pictures off of my iPhone 4S and on to my computer. However, when I plug my phone into my computer, open it up, enter the DCIM, and enter one of the couple of folders, the pictures won't load. It just sits there loading forever until I force exit explorer.exe . This never started happening until I upgraded to Windows 7, it worked fine on XP. Does anyone know what is causing this? I need these pictures!