Summary

When an Installscript function uses the new SYSINFO.WINNT.bWin81 or ISOSL_WIN81 constant to detect if the installer is running on Windows 8.1, the return value is FALSE.

Symptoms

When an Installscript function uses the new SYSINFO.WINNT.bWin81 or ISOSL_WIN81 constant to detect if the installer is running on Windows 8.1, the return value is FALSE.

Cause

The issue is due to the supported OS ID for Windows 8.1 was not added in the manifest files.

Resolution

Download and extract the attached manifest files to C:\Program Files (x86)\InstallShield\2013\Support and rebuild project.

Workaround

The manifest files will resolve the issue for Installscript projects, but will not work for Installscript custom actions in a MSI project. For MSI projects, check VersionNT for value 603 instead.