I have a Windows 2003 Standard server which is running as a Root CA. This CA has issued certificates through AD to our computers for use for authentication to our Wireless network. Today some of the user stopped authenticating to the wireless network. I tracked this down to the computer certificate being expired. I know these are not Level 2 certificates and thus will not auto renew. How can I clear the old certificate and issue a new one. I have tried to revoke the certificate and tried to issue a new one from the Certificate mmc on the client side. When I try that It gives me an error that I't can't.