For an installation package, the PageCount summary information property contains the minimum installer version required. For Windows Installer version 1.0, this property must be set to the integer 100. For 64-bit Windows Installer Packages, this property must be set to the integer 200.
For a transform package, the PageCount summary information property contains minimum installer version required to process the transform. Set to the greater of the two PageCount summary information property values belonging to the databases used to generate the transform.
The PageCount summary information property is set to null in patch packages.
This summary property is REQUIRED.
Win32 MSI APIs: MsiSummaryInfoGetProperty, MsiSummaryInfoSetProperty