You can add a Root CA Certificate in Windows through Microsoft Management Console. Kindly follow the below steps to add it.
- Log in to Windows Server.
- Open MMC.
- Click on File -> Add/Remove Snap-ins.
- Choose Certificates, then Add.
- Go to My user account.
- Click on Add again and this time select Computer Account.
- Move the new certificate from the Certificates -> Current User -> Trusted Root Certification Authorities into Certificates (Local Computer) -> Trusted Root Certification Authorities.