If you’re a sysadmin trying install a root certificate to devices for the purpose for SSL inspection, and you’re not wanting to leverage Group Policy for a widescale rollout just yet, here’s how you can script it to import silently via command line using your preferred administration tool:
certutil -enterprise -f -v -AddStore filename.crt
Replace filename.crt with the name or path to your certificate. No reboot should be required.