Hello,
All my desktop icons disappeared, including the taskbar last time I booted up. The background screen picture is still the same, but no icons. No matter what I click, nothing works. I tried cntr-F2, it just made the screen go dark and nothing else happened. When the system was first set up, at the log in screen there is a dropdown menu with several choices, and one of them is cinnamon, so I clicked on that, and it booted up with all my stuff saved, but I think it's an old version, because the update manager icon, though it says there are updates available, doesn't do anything when I click on it. The system does work, though.
I downloaded linux Maya 17 and have it on a DVD, but I am afraid to install it because I might lose all my stuff. I have a raid set up with two 1.5TB drives, and one 128gig solid state drive, mostly for the quicker boot-up.
I am really a novice with all this, the system was set up by someone who knew all this stuff, but is no longer available for advice. Any help would be greatly appreciated. I just had a plain normal Maya 13 desktop, with the usual icons and taskbar for normal use. Also had VM Ware with windows XP with a small amount of drive space.
Thank you

well, you have noticed the obvious: you are facing a re-install.
please choose an LTS version next time.

but first you have to understand on which partition your operating system is installed and which partitions are simply storing data. because you will not loose everything when you do the re-install right; even a relatively full-fledged gnu/linux like mint needs less than 10GB.
partitions is the magic word.
read up on it, understand where your linux os is and where the data is you don't want to loose.
once you understand, you can point out a partition that will be the candidate for the new install (or create one - i'd say around 20GB is sufficient) - and format only that one. so data loss will happen in only 1 partition. so you don't have to backup 3TB...

edit: i suspect that linux is installed on the 128GB SSD.

Thank you very much for the advice. Looks like I am going to have to learn some things here. I am really not computer savvy at all.

meanwhile, to give us some info that might help us help you, do this:
open a terminal, typeenter password when prompted.
copy all output and paste it here, between code tags.

Can't open a terminal! Nothing happens on the screen, no matter what I type. I am actually going abroad for awhile, so I will not be here to work on the computer. I'll pick this up when I return. Thanks for your help!