[reboot]

OK, you're going about things the hard way.
You managed to unzip (untar) the file, and they reside in the /root/tmp folder.
You now have to install the package.
In Gnome, there's two ways. The GUI way, and the hard way.
The hard way: Open Terminal (you must be in "root").
Change to the /tmp folder.
type ./configure and (hopefully) it will install.
You'll have to manually create a shortcut to it in the menu, or (once it's installed) choose the "Run" command, browse to the installation folder (usually /usr/share or /usr/bin) and run the program.
The GUI way:
Go to Configuration, Packaging, and open "Package Manager". From there, browse to the /tmp folder, highlight the .tar.gz file, and install. If you get any error, then the package must be done the hard way (above), compiled manually (./configure) and then run.