Oh dear, all these people who ignore the Stickys at the top of the sections they post in. There's a link there for you to update your installshield engines. Which is possibly indirectly the cause of your error. Although this one is a runtime error After updating installshield, also make sure you have an update version of Java: Java 1.4.2 (click on link) Best done before installing LW. But do ensure you have a solid connection when you're installing LW.