The Symantec Endpoint Protection (SEP) 14.3 Windows client may fail to install on Windows 7 or Windows Server 2008 R2 unless SHA-2 code signing support is installed. Both first time client installations and upgrades may fail with the following error:
Symantec Endpoint Protection can only be installed on systems with SHA-2 code signing support update (KB4474419).
After installing KB 4474419, if error messages about corrupted files are still seen during the SEP client installation, install KB 4490628 as this is a prerequisite for 4474419.
Endpoint Protection Version
Operating System
Lack of SHA-2 support for legacy operating systems, or unsupported Operating System (OS).
Install SHA-2 code signing support on legacy OS by visiting the site below.
https://support.microsoft.com/en-us/help/4472027/2019-sha-2-code-signing-support-requirement-for-windows-and-wsus
This issue may also occur if you attempt to install a newer client than is supported for the OS. Check the compatibility matrix linked below to confirm.
Windows compatibility with Symantec Endpoint Protection clients (broadcom.com)