If you used the Microsoft Edge browser with Internet Explorer mode to generate your Personal Authentication certificate, you can use the same browser to import and install your certificate.
Import Certificate into Edge Browser Certificate Store
First, download your certificate from your dashboard. You will receive a zipped folder containing your email certificate and a few optional chain certificates from the Certificate Authority.
In the CRT - CER Files folder, your email certificate file name will contain a string of numbers. Extract this file to import it into your certificate store.
To access the Edge browser certificate store, first go to settings and locate the Privacy, Search, and Services menu. (url: edge://settings/privacy)
Scroll down to the Security and click Manage certificates to open the certificate store.
The certificate store window will list any existing certificates installed on your machine, but it will not yet list the certificate you are currently installing. Click Import to import the certificate.
In the Certificate Import Wizard, click Browse and select the email certificate you extracted from the downloaded zipped folder, then click Next.
It is recommended to import the certificate to the Personal store. Click Next.
There will be one more page to confirm and finish importing the certificate. You should now see the certificate listed in your Personal certificate store.
Export Certificate PFX
After you have imported the certificate into the certificate store, you can export it as a PFX (personal information exchange) or PKCS#12 file, which can be installed on another device.
In the Certificate store, click the certificate to be exported, then click Export.
On the Export Private Key page, select Yes, export the private key, and click Next.
If this option is not available, the private key cannot be found in the certificate store, and you will need to re-generate the certificate using Edge with IE mode. You may be required to cancel and place a new order in this case.
For the Export File Format, select Personal Information Exchange - PKCS #12 (.PFX). The default checked options are recommended. Click Next.
On the security page, you can either select specific groups or users on this device or set a password for the certificate. It is recommended to set a password. You may want to save the password somewhere safe, as you will need it whenever you install the certificate on another device. The default encryption option is recommended. Click Next.
On the File to Export page, click Browse to select a location and enter a file name to save your certificate PFX.
The file extension should be .pfx.
Finally, you will confirm your settings and complete the export to obtain your certificate PFX file. You can install the PFX file on another device if necessary.