The msi file is signed upon release, the installation disk does not contain an unsigned msi.

If you need to remove the signature (e.g. for the purpose of transforming the msi file using the Orca tool), you can use a third-party application (for example osslsigncode tool).

Please refer to the online documentation, "Customizing the ActivID ActivClient Setup" for a detailed explanation on how to customize the ActivClient installer.