How to ativate avi file properties "Summary"?

[tharmon]

I would like to enter information in the "Summary" screen of Properties when you "right click" a thumbnail of a photo. You get there by right clicking Properties of a thumbnail, then click Summary- then click Simple. I like this screen for entering information about a picture (avi) but its not active! .... I can't enter the information! How do I activate it? and how come this same screen is available for the THM file that accompanies the avi file?

Thanks... Tom