Thanks for all the (apparently) excellent replies.
I was running 13.10, and had a pop-up that said there was a new version of Kubuntu available. I followed through with the instructions and restarted when told to do so.
now when I restart it doesn't get past command line. I see:
Loading Operating System ...
error: symbol 'grub_term_highlight_color' not found.
Entering rescue mode...
grub rescue>_ (with the flashing cursor, not frozen)
so, no, I don't have GUI. Re-install would be a problem since I upgraded from within 13.10.
So I followed the link and instructions for'boot-repair' to: boot from previous 13.10 disk, 'try Kubuntu' then from terminal get and run 'boot-repair' then restart.
I am now running Kubuntu 14.04 Trusty Tahr.
Thanks for the quick replies and help!