This applies to Windows 8 x64 Professional and Windows 7 x86 Professional, NIS 2014 V21.0.1.3.
On system startup, NIS.exe run 45-55% utilization for 60-80 seconds after the desktop appears. This is a constant high CPU usage for the 60-80 second period. It is the SYSTEM component NIS.exe. It is 100% repeatable and occurs on all my computers. NIS 2013 did NOT have this problem.
Turning off Enable Boot Time Protection and Early Launch Anti-Malware Protection and SONAR does not change this situation.