ok, well i downloaded itunes on my computer. anyway, that was fine and all, but now, i have a new computer which is much faster. can i redownload itunes on it? will all my previously downloaded music erase??

burn them onto cds and use itunes to load them off the cds.

You can put iTunes on it, but you'll have to copy your music over to it.

You should de-authorize your old computer if you don't plan on keeping music on it, too.

Burn your music to a CD and transfer it to the new itunes.