I was getting this error:
Microsoft SQL Server 2000 Reporting Servies
An error has occurred during setup
An Error has occured while performing the following setup action. Please select help for more information about this error. You may be able to skip this action by selecting ignore, or retry the action by selecting retry. Selecting cancel will end the installation of SQL Server.
Error Code: 1603
I found a blog entry by Aaron Myers that explained that you must have the user ASPNET on your localmachine. What a crummy error message.