To install a client certificate, follow these steps (your experience may vary slightly, however, the general concept will apply):

1. When you navigate to a site with an certificate that is not recognized, not valid, or expired, you will see a pop-up like the following:
   
   
2. To install the certificate, click on "View Certificate". The Certificate detail dialog will appear:
   
3. Select the "Certification Path" tab:
   
4. One at a time, select the nodes with a red X icon, then click on the "View Certificate" button.
5. The Certificate detail dialog will appear again. Click on the "Install Certificate" button and the "Certificate Import Wizard" will begin:
   
6. Click the "Next" button.
7. Ensure that the certificate is automatically stored (default radio button option) and click the "Next" button:
   
8. A final summary review screen will be displayed, click the "Finish" button:
   
9. A Security Warning dialog will appear, asking for confirmation of the installation:
   
10. Click "Yes" to confirm. A message box will appear, stating success or failure.
11. Click "OK" to close any Certificate detail dialogs.
12. On the original warning dialog...
    
    Click the "No" button.
13. Navigate to the URL again to test the installation of the certificate. If the warning appears again, repeat the steps above until all of the certificates are installed.