add video, “choose files to upload,” doesn’t work

I’m trying to add a .wmv file from my computer to a post on my blog.

When I click on the add video button it opens up the add video box.

However, when I click on the “choose files to upload” button, nothing happens.

Any help would be appreciated.

PS. I am using an older version of wordpress [2.7, I think?] because that’s what I’m most comfortable with, given the number of plugins I’ve been using for the last several years.