Hello!
I've developed the service. It is encrypted and signed. It is loaded on demand by another application. My service has 500-600ms boot time in Windows 7. The same service (the same executable file) has 800-1000ms boot time in Windows 8. I've done a lot of research and discovered following: if Windows defender service is disabled my service boot time is 500ms.
Almost all boot time (95%) is spent on container init operation. It means that almost all time is spent on loading executable image into memory. Two root causes are available: Windows Defender and Filesystem Filter Driver. How can I return previous service performance without Windows Defender disablement?