Sometimes, if you use Fedora 18 – Spherical Cow, the Software Upgrade program couldn’t work properly. Software Upgrade shows you all the available upgrades but it is not able to install them. The download process starts but it will never finish and you wait for hours with no results. When and if you have this problem you can easily solve it launching a Terminal and typing the command:
In few minutes (depending on how many updates you need) your Fedora will be updated perfectly.
Last but not least, if you want to have a list of all the potential upgrades on your OS you can type:
yum list updates