Hi everyone, Linux scrub here. I recently switched to Ubuntu 13.04 from Windows, and everything has been going great up to this point; I've received a lot of great help and advice from this community, and haven't had any real, big problems until now.
But today an update I installed through the normal system update tool has completely broken my desktop after the login screen (which displays fine). Normally my desktop looks similar to this:
But after today's update, it looks like this, without the left side bar or the clock bar along the top:
I can still get into the terminal through keyboard shortcuts and access all my files by going into the folders, but the navigation bars have completely vanished. Additionally, if I open a window there's no bar along the top (where the close and min-max buttons normally are), and trying to drag it around makes my system chug like something else. Is there any way to roll back the update or install and activate another desktop environment through the terminal? or perhaps do an install repair from the Ubuntu install boot disk?
Thanks in advance for all your advice. I really enjoy the OS, and I hope I can get this fixed without too much trouble.