After installing Certificate Services on a server and configuring it to be either an Enterprise Root certification authority (CA) or a standalone certification authority on a server, you cannot immediately request a Web server certificate by using the Web Server Certificate Wizard on that same server. The Send the request immediately to an online certification authority option is grayed and cannot be selected.

It takes a few hours for IIS to recognize that a new CA has come onine. After IIS recognizes the new CA, re-run the Web Server Certificate Wizard to generate the certificate request. The Send the request immediately to an online certification authority option will then be available.

If you must have a certificate immediately, run the Web Server Certificate Wizard and select Prepare the request now, but send it later. The wizard will generate a certificate request file that can be processed immediately by the new CA.