Delete the key pair that is used with Microsoft Outlook on Windows.

1. Right-click the Start button and then click "Control Panel."
   
   
2. Click "Network and Internet."
   
3. Click "Internet Options."
   
4. Click the "Content" tab and then click "Certificates."
   
5. In the "Intended purpose" pull-down menu, select "Client Authentication" and then click "Remove."
   
6. Click "Yes."