Please see the link below
https://help.ubuntu.com/community/32bit_and_64bit

That just tells you if the CPU is 64bit, not the OS installed. It's
perfectly acceptable to install a 32bit OS on 64bit hardware and it
will run, just not as efficiently as the full 64bit instruction set
isn't available to it

Open up a terminal window [ Applications / Accessories ] and type the
following then press [Enter]

uname -a

If you see x86_64 in the output line then you have the 64bit version,
however the version you get depends on which ISO you downloaded to
create the installation CD. The default 'download' button on the
Ubuntu site would have got you the 32bit one - you have to select the
64bit version from a drop-down list.

Thanks for that .. x86_64 is in the $tring...magic, I took a chance
with the AMD 64 distro.

All that I need now is either Gnome3 or Unity front end as they both
seem faster than Gnome 2.30.2 installed with ubuntu 10.04.1, having
downoaded 11.04 and 10.10 live discs.

Play with Unity / Gnome3 by all means but be aware that both of these
were not written for Ubuntu 10.04 and you may end up needing to erase
the whole OS and start from scratch when it screws up. Don't do this
on any system you can't afford to lose

at this stage I only experimenting and at the
same time familiarising myself with (to me) an alien system, as I did
when swapping from dos to win3.1... linux seems like dos with windows
doesn`t it?? struggling with command lines again.

I`m interested in linux `cos it costs` nothing :) but more important
it`s supposed to be more secure tham micro$oft and it`s fun...

I would like to install gnome3 or unity because they seem quicker and
more complete than gnome 2.3 and have tried to download from conical
but it seems that gnome3 is unavailable :( ...oh well.. even tried
grabbing it off the 10.04 for netbook distro...might install 11.04 for
unity gui as it`s even better...

Linux has advanced far enough so that the command line isn't as
prevalent and many users do not even need to go there, in the same way
that many Windows users never have the need to use DOS.

I can remember the hoops we had to jump through to add new devices to
Win3.1 all those years ago - no plug and play then