Highlight certificates in the available snap-ins section and click Add
Once the certificates snap-in window appears, click computer account then Next
Select Local Computer, then click Finish
Once the Snap in window is closed, look for the area in the middle section with "Certificates (Local Computer)"
Double-click to open it, which should show you an image as shown to the right
Right-click "Trusted Root Certification Authorities", and select All Tasks -> Import...
This will open the Certificate Import Wizard. Hit next, then click on Browse and search for the certificate you had downloaded earlier. Once it's selected click on Next.
Make sure that the "Place all certificates in the following store" is checked and the "Certificate store" is "Trusted Root Certification Authorities"
Click Next and then click on Finished
The pop-up message should say "The import was successful."
How to install Computerisms Certificate Authority into your Thunderbird mail client
To add the certificate to Firefox, start by opening Firefox
Click on the top right menu bar (looks like 3 horizontal lines)
Click on Options
Step 1: Click on Advance in the left menu bar
Step 2: Select the Certificates tab in the top menu bar
Step 3: Click on View Certificates
Click the Authorities section tab
Click the Import button
Navigate to the Desktop and select the file named Computerisms.Root.Certificate.pem
Click on open
Check all the options and click on OK
Note that the last option, "Trust this certificate for identifying software makers", is not required. You may leave this unchecked, but the other 2 options are required.
