I am not sure quite how this happened, I was in
the middle of configuring the root certificate authority using my notes which I
have implemented loads of AD CS infrastructures (http://blog.ryanbetts.co.uk/2015/01/implementing-two-tier-active-directory.html)
and until today I have never had this issue before. The only thing was that VMware
Tools restarted the VM when I was in the middle of configuring the Certificate
Authority.
When you try and start the AD CS service you are
faced with the error “A certificate chain processed, but terminated in a root
certificate which is not trusted by the trust provider. 0x800b0109 (-2146762487
CERT_E_UNTRUSTEDROOT)”.
It was a simple fix, but threw me for a minute.
You need to manually import the root certificate that is generated and placed
in the C:\Windows\System32\CertSrv\CertEnroll folder on the root certificate
authority itself.
Install the certificate in the Local Computer
store and have the wizard automatically choose which store it places the
certificate into.
You should then be able to start the AD CS
service.
