can’t access images

I’m trying to add an image to a post. I click on the “add media” link. An overlay screen pops up. Under “From Computer” I click on “Choose files to upload” but nothing happens. It doesn’t direct me to another screen, there’s no pop up to search my computer, nothing. It just sits there. So how can I get my images inserted into the post. I checked other upload problem posts but didn’t see this particular problem. So how can I get the files into a post?

Thank you.