During the installation of SEP 14.2.4814.1101 64 bit by removing the 3rd party antivirus software (Kaspersky Endpoint Security 11.0.1.90), Kaspersky uninstalls correctly, but after the computer restart, SEP doesn't work and we can see an installer window with information "installation interrupted". Your technical support couldn't help us and advised us to submit an idea on Symantec webpage.
Please improve the removal function. It would make upgrading Symantec way much easier.