Upgrading

I am running Ubuntu 10,04LTS on my machine. My Linux CNC is EMC2 , 2.4.6 I would, like to upgrade to a newer addition, but before I do I would like to get some answers to few questions.
My machine is running Windows XP and has 15.9 GB of memory 3.3 of it is used and the other 12.5 is available for programs. When I run a latency test I have no problem meeting the prerequisite for reliable operation..

Would it be the best if I were to start with a fresh download of Linux and also LinuxCNC?
Or would it be better if I were to upgrade what I have? If I go this route can I go to the latest edition or will I have to step through a couple of upgrades?
What flavour of Linux would be the best for my hardware?

First of all some idea of your hardware would be a good start. Then a recommendation can be made.

The XP machine and the Ubuntu machine are they the same or different machines, that was not quite clear.

So if you can supply a good breakdown of your hardware we can go from there.
1 being the existing machine
2 being the XP machine (if they aren't the same)
3 being whether you are using the Parallel Port or Mesa Hardware

The simplest route would be an install using the official debian based images or you may want to look here forum.linuxcnc.org/9-installing-linuxcnc...t-19-2-with-linuxcnc

The first page list the releases from most recent to oldest.
Some people feel more comfortable with Mint others with Debian.

Thanks for your reply. Yes Ubuntu and XP are the same machine. I am not using Mesa hardware.

Ok that's a start.
Now to advise which is the best option a description of MB or computer, including CPU and installed memory will help as well. Saves me having to search for the MB or computer model then trying to guess what cpu you have.
If you machine does not have a 64 bit capable cpu wheezy maybe your best choice.

Thank You for the reply, the machine has 15 GB memory 3 are being used leaving 12 available. As for the other question answers I will have to look at the machine info and get back to you.

Is that total memory or installed RAM plus swap ?

How much RAM is physically installed ?