If you try to install a version of Worship LIVE! (or our other software) that was released before Vista, it will probably not install correctly, and will complain that certain files were not properly installed, and ask you to reinstall the software. That is a valid error - because Vista's "User Access Control" features try to prevent unauthorized software from affecting the operating system. But it's a little bit TOO aggressive at this attempt.
So be SURE to install it with administrator privileges - you must log into Windows as an administrator, or run the installer with admin privileges; installing it with limited privileges will usually cause problems properly registering files for the software to use.
Also, if you still have trouble, the software will run fine under Vista and Windows 7 if you run it in Windows XP compatibility mode. The software needs to have elevated privileges to run properly in Vista. Please review http://support.microsoft.com/kb/292533 on how to do this, or review our own KnowledgeBase article.