今天在玩CentOS的时候出现了：

Error: cannot find a valid baseurl for repo: rpmfusion-free

这个问题真到好恶心啊，以前一直使用到是ubuntu，最近切换到CentOS以后，各自小白啊。最后搜索到到答案是：

You seem to have added the RPM Fusion repository incorrectly. Let's start clean. First remove the repo with:

rpm -e rpmfusion-free-release

Then re-enable it using:

rpm -Uvh http://download1.rpmfusion.org/free/el/updates/6/i386/rpmfusion-free-release-6-1.noarch.rpm