Use Add/Remove programs from the Control Panel (Start, Control Panel, Add/Remove). Find Kazza on the list and click to uninstall.
This might un-install the spyware to if its linked to it, in which case, good.
If not, and you should already have anyway, a Spyware Remover.
A good one is Spybot, Search and Destroy. Find it here:
Download, and install it, and then update it. Finally run it, and delete anything it finds as spyware.
it also comes with a program called TeaTimer, which when selected to run will run in the background, coming up with messages everytime the registry is about to be changed. This is good since if spyware doe get onto the machine and a message pops up you don't know about, click to dissallow it.
If you are installing a program though and this feature is still running, right click on the logo in the taskbar on the right and close the program off, since you'll always be getting messages about registry changes
Another good spyware remover is Adaware:
If you want to, run both, since one will find some things the other can't and so on and so forth, so you feel safer. I only run Spybot though at the moment. I had problems with Adaware, but no one else seems to, so don't let that put you off
I hope this helps