No, don’t remove Active Directory otherwise you will experience troubles with other services of Server 2012 Essentials. I tried once to remove it as I thought I didn’t need that. But it’s really not easy (if possible at all. Read) to replace the Domain with a Workgroup.

Some info on that here: http://m.winsupersite.com/article/windows-server/windows-server-2012-essentials-domain-workgroup-144357

And more info on connecting from a workstation that is not in the domain here: http://m.winsupersite.com/article/windowsserver2012/windows-server-2012-essentials-connect-client-pcs-domain-144329

It’s most probably because your client PC is not in the domain that you experience troubles…

I have just installed a new Server 2012 Essentials for testing purpose and didn’t experience any issue to remotely connect with RDP… See my post where I took note on how I have fine tuned Server 2012 for my own need : /wordpress/fine-tune-server-2012-essentials/

You could finally also be interested in this post about remote access to Server 2012 from anywhere: http://m.winsupersite.com/article/windows-server/windows-server-2012-essentials-access-server-remotely-144435

Do I need to remove Active Directory?

thanks