By windows 7 email I assume you mean Windows Live mail. The snip isnt from that. what email app are you using? It almost looks like something from office.
It's Outlook 2007 by the looks of things. You won't get a "Send" button until you have set up your email account, including details of the outgoing mail server.
You can set up your email account in Outlook by going Tools > Account Settings > Email tab > New
If you have any probs with that, please post back and I'm sure we can fix it