SEP version 11 does not install on Windows 8.1

I got the first computer running Windows 8,1 in the company and when I try to install SEP (version 11.0.6300.803) the setup application sends an error "This program has compatibility issues".

Forther details says SEP has been blocked from running because it might prevent your PC from starting correctly in the future.

This is the CEO computer and can not be running without antivirus. Please help.