Is Ubuntu compatible with my hardware? [duplicate]

I am a bit financially strapped and received a Gateway GT5056 tower. The tower has an AMD dual core 64-bit processor in it. Will Ubuntu 12.04 run on this machine? I will not have any other application other than LibreOffice installed.

You can confirm if it'll work or not by downloading the Live CD ISO and booting with the Live CD. This will not install ubuntu on your machine, but will let you run it for the session. This way you can verify if all your hardware is supported.

You can try Lubuntu, which is a lightweight version of Ubuntu with a very fast and light window manager.

For an old box and since you already won't install any other application except Libre Office; I would suggest installing lubuntu http://www.lubuntu.net/ which is a fast and lightweigh Ubuntu derivative that is designed specifically for low resources computers.

Libre Office doesn't come by default so you will need to install it https://www.libreoffice.org/download/libreoffice-stable/

Yes, Ubuntu 12.04 will run on your Gateway GT5056 tower. You can use either the 32-bit or 64-bit versions of Ubuntu, both will run just fine. If you have performance problems with Ubuntu, you can install Xubuntu instead which should take less resources than Ubuntu, however Ubuntu 12.04 should run alright.