Install Fails – The theme is missing the style.css stylesheet.

Hi
I’m just learning how to work with WordPress themes. Originally I paid to have the theme installed but then I screwed up that initial install so I wanted to wipe the slate clean and start again. I deleted that initial install but now when I try to upload the theme it fails with the following message “The package could not be installed. The theme is missing the style.css stylesheet. Theme installation failed.” I’ve attached the file that I downloaded when I purchased the theme.