How do I get back ONLINE?

[pcvc]

Win7 netbook - Just wanted an easy email client so I won't have to use M$ to get my Gmail.
Every so often, ZD decides there's no network connection and goes offline on its own, regardless that I have a perfectly fine connection and everything else online works/access internet fine. THEN - it REFUSES to respond in any way at all when I click "online" to tell it; "yes, there is access, go get my bloody mail!!!!" :-)
That's ALL I need this thing to do - just get, and send emal. Everything else means nothing to me.
Any thoughts on how to get it back online again??