Auto-Align won't come up

When I try to use the Auto Blend feature of Photoshop CS5 it does not come up highlighted and I can't use it! How do I activate this feature? It is found under the edit menu. Also when I tried to update, a message comes up to close Photoshop .exec. What is this and where is it and how do I close the program in order to complete the updates I want??? Thank you so much for any help you can give me. I am sooooo frustrated!