There seem to have been a lot of questions about Kazaa and Kazaa Lite recently so I hope this helps.
Kazaa is what is known as a p2p file sharing program. This means that millions of people are connected over the internet and you can copy files from each other. As there are an awfull lot of idiots out there though, you have to be carefull. When you run a search you get a list of files and if you move your mouse cursor over a file, an info box is displayed which you should read before starting to download. A lot of stuff is bogus and has bee re-named but the original name is usually somewhere in the info box.
A fair amount of virus's are mixed in as well, so make sure you have decent Anti Virus software and that it is up to date. I run the live update every time before I connect.
Then make sure you check everthing you download before you open any files. If you are carefull and use a bit of common sense you will be able to use Kazaa Lite Safely.
The original Kazaa is full of spyware which is bad news so Kazaa Lite has been developed and this is clean and contains no spyware or hidden programs and is the only one to use.
The best site to get it from is
http://doa2.host.sk/
Just follow the download links until you get to a list of kazaa lite stuff. Then downlaod this one
Kazaa Lite K++ 2.1.0 build 3 English
Or another language if you want but the numbers are the important bit. The higher the number, the newer the version is.