Is it possible to add music onto iPods via Windows Media Player?

I got my iPod about a year ago. My computer crashed and I haven't been able to download iTunes again to put music on my iPod. I've recently added more music to my computer and would like to add it to my iPod. But, I'm afraid that in doing so, it will delete all of the music that I already have on my iPod. Can you guys help me? I'm iPod illiterate! Help!