The first thing I would try is to uninstall LW and all Java versions installed on your computer. Then download the JRE offline installer (version 1.5.0_07) from the official Sun page:
http://java.sun.com/j2se/1.5.0/download.jsp
Install it and then reboot and install LW again. See if it makes a difference.
If not, then you'll have to uninstall the both programs you've mentioned (crazy voice and Nero 7) and check whether LW will run when those programs are removed. If it does, reinstall first Nero and try LW again. If it still works then reinstall Crazy Voice. You either end up with all working fine or with LW not working again, which would mean that Crazy Voice is the problem.
