Welcome to LinuxQuestions.
A linux distribution is in a nutshell the kernel plus all the other supporting software. There are hundreds of linux distibutions. You can get an idea whats out there by looking at
www.distrowatch.com. Ubuntu, OpenSuSE, Fedora, Mandriva are just a few of them.
So which one are did you install? As already stated you have not provided enough detail to know what your problem really is or what help you need. Not sure what you really mean by Media test failed. Your laptop has wireless, ethernet and a built in dial up modem. Which one are you trying to get working?