In some cases while installing MicroStation for Orchestration framework on a Windows 2003 server system an error “Error 1718 file was rejected by digital signature policy” occurs. This is caused by Windows Installer because it uses Software Restriction Policies to verify the signatures of signed .msi package files and if a .msi package file or a .msp package file is too large to fit into a contiguous piece of virtual memory, Windows Installer cannot verify that the package is correct.
To avoid this you should have a large enough and not fragmented paging file. (To avoid paging file fragmentation allocate whole paging file at once).
Or download and apply Windows 2003 server hotfix KB925336.
Details and more information could be found here:
http://support.microsoft.com/kb/925336
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