Windows Large MSI MSP Install Error 1718 Event 1008
I have experienced this problem while installing WebSense 7.6.2, if you are getting Error 1718. File FileName was rejected by digital signature policy as me, the root cause of it can be the large .msi or .msp file you are trying to install. Additionally, the following event may be logged in Application Log.
Event ID: 1008
Description: The installation of FileName is not permitted due to an error in software restriction policy processing. The object cannot be trusted.
This problem occurs if the Windows Installer process has insufficient contiguous virtual memory to verify that the .msi package or the .msp package is correctly signed.
If you are using Windows Server 2003 you can install the fix below.
For more information and other solutions : http://support.microsoft.com/kb/925336