This post is about Health key and certificate management service, IP helper service, Local session manager service, and IPsec policy agent Windows system services:
1) Health key and certificate management service: Health key and certificate management Windows service is used for managing health keys and certificates used by Network Access Protection (NAP). If this service is disabled then, some of the services related to VPN will not work.
2) IP helper service: IP helper Windows service is used for providing IPv6 (Internet Protocol version 6) connectivity. If this service is disabled then, network connections will not work in your computer if your computer is using IPv6.
3) Local session manager service: Local session manager Windows service is used for managing user sessions. This service is required for the Windows operating system to run. If this service is disabled then, Windows will not start up normally.
4) IPsec policy agent service: IPsec policy agent Windows service acts as an agent in retrieving IPSec policies. This information is then passed along to other IPSec drivers. IPsec policy agent service is also used for managing the firewall remotely. If this service is disabled then, services and drivers which depends on IPSec policies will not work. Also, remote firewall management will not be possible.