E-mail, chat, & VoIP : disappearing Outlook express

disappearing Outlook express

I read the outlook mesages and none seem to apply. My problem is that Outlook express just shut down. If I click on it all it does is hiccup. I recently downloaded IE7 about two months ago and I'm wondering if that is the problem. It was working fine until I sent and unsubscribe email to a site. I think that couldn't be the problem. I have racked my brain and two days looking for an ans in MS web site but no avail. Any recomendations. If I remove IE 7, will IE6 still be on the computer?
Thanks from the old dinosaur.