When an install of Symantec Endpoint Encryption has occurred, but has failed, the error code is the typical 1603.
Symantec Endpoint Encryption has pending reboot detection so if a system is pending a reboot due to the following scenarios, the install will halt:
1. Windows update pending reboot.
2. Third-party update pending reboot
3. SEE install\update pending reboot
If the SEE Client installation process detects any of the above, the error will be reported accordingly, but will not tell you the install failures was due to a pending reboot.
This topic as well as other important topics are discussed in our Best Practices article and is encouraged to consult.
Symantec Development has created an additional script that can be used to detect if the failed install was due to a pending reboot.
In order to obtain information on this, please contact support.