Hi, I have install CA and am Confused on Step 2. How can I do a GUI Interface to generate the c:\certreq.txt instead of the command. In addition, by default exchange have Self-signed certificate, how do I know the users are using the exchange self-singed certified to access OWA or using the CA to access the OWA? Lastly, how to removed the Self-signed cert in exchange 2007 and ensure it is using CA? Tks ============== 1. Install an Enterprise CA on a server. 2. On the CAS server, use the New-ExchangeCertificate task in Exchange Management Shell to create a new certificate request. For example, new-ExchangeCertificate -generaterequest -domainname domain.com,mail.domain.com,autodiscover.domain.com,machinename -path c:\certreq.txt 3. From the CAS server, enter http://CA_server/certsrv