I've had problems with all distros you're trying but have to say i
found Xubuntu perfect for everything so far.

Let me get this straight. You are using Linux Mint and not Ubuntu 12.04.
The title suggests 12.04 is the problem, but you say it is on Mint 13. Am I
missing something?

They are different beasts. Mint uses a different desktop and window manager
from Ubuntu. There are several versions of Mint 13 as well, Mate, Cinnamon,
and KDE. I cannot picture your screen or problem until I know more.

I am trying to use Ubuntu 12.04 and getting problems as described.
So to use my PC I have to use either Win Vista, or Mint 13.
The problem on 12.04 and 11.09 is that on my login ID I have no
launcher at all. If I log off as my ID and login as guest the
launcher is visible but the permissions don't allow doing much.
I have been told I can bring up the launcher by putting my mouse
pointer to the left side of the screen and it will be visible.
Doesn't work. In order to get the system to reboot is to power
down and reboot and pick one of the other OS's. I am trying to
get back to a Ubuntu product, saying I should be able to adapt.
Doesn't look like Ubuntu is going to be it. I think I may try
Xubuntu latest next.
Sorry if my first post was confusing, you should be in my shoes
and I hope this post clears up my situation.

Auto hide must be on. Try clicking on the menu in the top right corner
of your top bar. Then system settings. Then click on the appearance
icon. notice the file button at the top of the window called behavior.
Click on this and then make sure the switch on the right says that auto
hide is off.

That should do the job but if not ask again.

What I have been trying to get across is there is nothing to get to
on any of the sides, I tried two different loads, couldn't get to
anything.
I have since loaded Xubuntu 12.04 and I am using it and learning to
like it. I still have Mint 13 loaded on another partition but I am
about to give up on it, I think I will leave it for a while just in
case I need another boot device for some reason.

Thanks for the ideas, not sure what happened with the two different
loads of Ubuntu 12.04 but there was no way to move forward with it.

I haven't tried Xubuntu on this PC so maybe I will it may be
a lot easier to get my mine around.

I switched to xubuntu for 9.04 or 9.10 to trial and then installed
10.04 on my main pc. It does everything perfectly without being
bloated - that's why i like it. Perhaps bloated is an unfair term to
use... i like the minimal install to which i add rather than with
ubuntu i would remove and add to get my setup as i liked. And i don't
want all the "bells & whistles".

couple of minor examples
e.g. Bulk rename - for all those photos... it's simpler and yet
quicker than Krename or the other one (can't remember what it's called
now).

e.g. I've just been trying to sort out a dot matrix printer today as i
had to get some urgent letters posted (wanted to send them recorded so
needed to get to the temporary village post office only open on a Tue
and Thu), inkjet cartridge died (only happens at the most inconvenient
times!) and lastly but not least [as the saying goes!] the car is off
the road. I was delighted that when the printer hung i could just go
into the menu and delete the spooled print jobs - in ubuntu i had to
do that on the command line i seem to recall but it was a while ago
now.

Xubuntu i have found is very stable, a great bunch on the xubuntu list
[not that this crowd aren't a helpful friendly lot] - but i haven't
needed much help! I did try Mint and it mucked up my memstick somehow.
Mint xfce is nice on eye candy... you'll miss that with xubuntu. I'm
always keen on "what's under the bonnet" - and that is where xubuntu
is better than others.

Stick xubuntu on a spare pc and have a good trial for a few weeks is
what i'd say - i think you'll be converted. I'm so keen on xubuntu
i've joined the documentation team.