No thats not how p2p works...You downloaded a clean version of LW..
Then when you decide to start downloading files it's all in your hands as to what you choose to download, there are so many viruses out there and you downloaded 1 file with a virus, you opened it without scanning it with your AV and now it's infested your computer...
P2P is filesharing with millions of others all over the world...
Limewire is just the software that connects you to them....
Go to Norbiesworld....