Installing the S/MIME Certificate on your Windows System
You can use Client Certificates, also called "S/MIME", Client or "Personal" Certificates, with most e-mail clients to digitally sign or encrypt e-mail. Client certificates are provided through the InCommon Certificate Service. For more, including how to get a certificate, see the S/MIME Client Certificate section.

When you receive your certificate from InCommon, it will be encrypted in the PKCS 12 format (.p12 or .pfx), using the pass-phrase or PIN you created for it at the time of request. You will need this pass-phrase to install the certificate.

Importing the certificate
To use an SMIME/ Client certificate, you must first make sure that the certificate has been imported and is ready for use.

1. In Internet Explorer, in the menu bar, click "Tools". Alternatively, click the gear icon located at the top right-hand corner of the browser.
2. From the drop-down menu, select "Internet Options".
3. In the "Internet Options" window, click the "Content" tab, and then select "Certificates".
4. In the "Certificates" window, click "Import..." to open the "Certificate Import Wizard".
5. Click "Next", and then browse to the location where you have saved your security certificate.
6. Note: If your certificate has a .p12 or .pfx file extension, you may need to select All Files (.) from the file type drop-down menu in order to see your certificate.
7. Select your certificate and click "Open", and then click "Next".
8. Enter your "pass-phrase" or the "PIN" that you used to secure the private key, and then click "Next".
9. Note: It is recommended that you select the "Mark this key as exportable" option, as this will enable you to export the certificate and its private key.
10. Leave the default choice set to place all certificates in the "Personal Certificate" store, and then click "Next".
11. Click "Finish", and then click "OK" to close the "Certificate Import" window.
12. Your certificate should now be imported to the computer.