Summary

Symptoms

If you include a Windows Installer 4.5 for Windows Vista prerequisite in your project, and it needs to be installed on a target system, the installation installs it. However, the target system behaves as if the prerequisite was not properly installed, and the installation attempts to install it again. This applies to both of the following InstallShield prerequisites:

• Windows Installer 4.5 for Windows Vista (x86)
• Windows Installer 4.5 for Windows Vista (x64)

Cause

The issue occurs because the conditions in the aforementioned InstallShield prerequisites are not configured correctly.

Resolution

To resolve the issue:

1. Make a backup copy of Windows Installer 4.5 for Windows Vista (x86).prq and Windows Installer 4.5 for Windows Vista (x64), which are installed to the following location:
   C:\Program Files\InstallShield\2010\SetupPrerequisites
2. Download the two hotfix files from the Attachments section of this article.
3. Extract the two .prq files from the .zip files to the aforementioned location.
4. Rebuild any release that uses these InstallShield prerequisites.