In short no. For limeware to work you have to tell the firewall to let it access your computer. this allows the program to access your PC through a port. If you have given permission for limeware to access through the firewall then anything that comes in on the limeware stream good and bad will be permitted into your computer. I suggest you run an anti virus program as well as the fire wall but even this combination will not guarentee that your PC stays free of viruses and other malicious programs. If you are using limeware or anyother insecure program to exchange files over the internet then you cannot be completely safe from the little nasties that live and breed in cyberspace.