Here's the website:
http://www.winguides.com/registry/display.php/1209/
It also has some other nice tweaks for windows, but make sure you know what you're doing when you edit the registry.
tricks: First, try to use the tweak above, restart and try to delete it again. If that doesn't work, restart again, press F8 during boot and select Safe Mode with Command Prompt. Then find your file using cmd and delete it. This works for me all the time. I usually try some other methods beforehand, but this is the most reliable method I know of.
I don't remember, but I think K-Lite has an option during uninstall or install to remove all settings. If it doesn't, you can uninstall it, and then search for kazaa and k-lite on your computer and delete pretty much everything that comes up (make sure you know what you're deleting though). Do the same for the registry (be even more careful with that).