Open-software what??

Following the readings on Mark's blog and his class on open-sofware I have to say I now posess a few more tools to familiarize myself with this incredible world that is Internet. It seemed like these softwares, programs and others are easy to use, good, without viruses and all the advantages said before. However, all these Microsoft things are the ones I'm using right now!! Since I'm not really familiar with this world, i used what I knew and now every readings I make are telling me to switch for Mac, or Mozilla, or to forget Vista, wich is what I have. I'm use to use Explorer, Microsoft and all that software 'junk' full of bogs and viruses as they call it, should i now change?? Do I have to ajust and learn about all these other new things? Are they really better?.... Or is their lobby only more organized and well paid so we get that information about their product being better?? Hum, wich sources are really truthful....