It is very easy to infect your computer with viruses. It is almost as easy not to infect your computer, but you will have to do some reading and adjust how you use Limewire.

Fake files showing up in search results
How to filter porn & spam
How to find music
What you should know about WMA files
How to use Bitzi

In a word, there are people out there who want you to infect your computer if you use Limewire to download copywrited material. Follow the advice in the above threads and get some antivirus protection if you don't have it.

Good Luck

Dano