As the import of certificiate varies between different operating systems and applications there is a choice of the most used ways given.
Within Windows most application uses the Windows truststore. Some applications like Firefox and Thunderbird use their own truststore.
To install a certificates to the Chrome Truststore go to Settings.
Screenshot Chrome Settings
On the Settings tab choose Advanced
Screenshot Chrome Settings Advanced
Scroll down to the Privacy area.
Screenshot Chrome Settings Privacy
Use Manage Certificate to enter the Windows Certificate Store for Browser.
Continued with Windows Certificate Store for Browser.
To install a certificates to the Internet Explore Truststore goto Settings - Internet Options.
Screenshot Internet Explorer Settings
In the Internet Options goto the Privacy tab.
Screenshot Internet Explorer - Internet Options - Privacy
Use Certificate to enter the Windows Certificate Store for Browser.
Continued with Windows Certificate Store for Browser.
Screenshot Windows Certificate Store for Browser
To install a root cartificate go to tab Trusted Root Cerification Authorities.
Screenshot Windows Certificate Store for Browser - Trusted Root Cerification Authorities
Use import to install a root certificate.
Screenshot Certificate Wizzard Step 1
Start the import with Next.
Screenshot Certificate Wizzard Step 2
Choose the root certificate file and Next.
Screenshot Certificate Wizzard Step 3
Make sure the store Trusted Root Cerification Authorities is chosen and Next.
Screenshot Certificate Wizzard Step 4
Use Finish to complete the import.
Screenshot Certificate Wizzard Confirmation 1
Check the fingerprint presented with the fingerprint of the root certificate and confirm with Yes.
Screenshot Certificate Wizzard Confirmation 2
At the end the import confirmation is given.
To install a intermediate root cartificate go to tab Intermediate Cerification Authorities. It is recommended not to import each intermediate certificate seperately better use the bundle.p7b file.
Screenshot Windows Certificate Store for Browser - Intermediate Cerification Authorities
The import steps are similar to the ones for the root certificate import. Only the third step is different.
Screenshot Certificate Wizzard Step 3
Make sure the store Intermediate Cerification Authorities is chosen.
As there is no certificate import in Edge the certificates need to be imported either with the Inernet Explorer or with the Microsoft Management Console.
To start the Microsoft Management Console press once the Windows key and type afterwards mmc.exe.
Screenshot Certificate Wizzard Step 3
Select mmc.exe and allow the User Account Controll to modify the data with Yes.
Screenshot Certificate Wizzard Step 3
Use File - Add/Remove Snap-in... to open the certifcate area.
Screenshot Certificate Wizzard Step 3
On the left habd side select Certificate and Add it.
Screenshot Certificate Wizzard Step 3
For the Root and Intermediate Root Certificates it is recommended to use the computer account. For the personal certifcates of course use My user account.
Screenshot Certificate Wizzard Step 3
Screenshot Certificate Wizzard Step 3
To install a certificates to the Firefox Truststore go to Options.
Screenshot FireFox Options
In the Options choose Privacy & Security tab.
Screenshot FireFox Privacy & Security
Use View Certificates to access the Certificate Manager.
Screenshot FireFox Certificate Manager
On the Authorities tab the Root and Intermediate Root Certificates are imported.
Screenshot Chrome Settings Privacy
With Import the process is startet. It is recommended not to import each intermediate certificate seperately better use the bundle.p7b file.
Screenshot Chrome Settings Privacy
To finish the import both checkbox should be tixked for grant trust to the imported certificate and use OK.