I am a newby to linux. However I have been using computers since 1964. I started learning about Linnux with the book "Linux for Dummies" There was a cd with Fedora and Ubuntu iso files. I installed Ubuntu (version 9.4 I think) in an old PC with Win 7 Pro on the C drive and put Ubuntu on a 240 ssd. planning to dual boot. After I was a little familiar with it I thought I would see if there was an upgrade version. I learned that my version was so old that upgrade was no longer supported.
My question is can I install one of the version 12s along with my present one or should I uninstall my present version before I install a newer version or am I not asking the right question?

Have a look here:

https://help.ubuntu.com/community/EOLUpgrades

Thanks Snowpine

You could tri boot if you wanted.

It always used to be said that you never upgrade. Installers warned that it may fail and still may fail. I still try to avoid upgrades. I know folks here suggest it but just so you know.

Since you say old computer you may wish to simply try a live cd/dvd of whatever you wish to try next. Be sure the live cd offers close to what you want. There has been some issues with older hardware on new ubuntu.

Thank You Jefro

If that computer support W7 like you said. I am sure it will support Ubuntu 12.04. So I would probably suggest an upgrade if you can. follow the steps from that link on post#2

With a fresh install you will have to go back and re do all setting and re install the peripheral such as printers and stuff, I personally wouldn't like that.

Good luck to you!

Upgrade to Linux Mint 13.

What are the hardware specs or Make & Model of computer?