Firstly when your issuance email arrives it will contain your web server certificate. Copy your web server certificate into a text editor such as notepad including the header and footer. You should then have a text file that looks like:
-----BEGIN CERTIFICATE-----
[encoded data]
-----END CERTIFICATE-----
Make sure you have 5 dashes to either side of the BEGIN CERTIFICATE and END CERTIFICATE and that no white space, extra line breaks or additional characters have been inadvertently added. Save the certificate as yourdomain.txt.
Test your certificate by using a browser to connect to your server. Use the https protocol directive (e.g. https://your server/) to indicate you wish to use secure HTTP. The padlock icon on your browser will be displayed in the locked position if your certificates are installed correctly and the server is properly configured for SSL.