Exchange 2010 CSR using Exchange Shell

Be advised: You may copy and paste the below commands into your favorite text editor such as Notepad or Notepad++ in order to customize them to suite your needs. We provide them only to show the structure of the New-ExchangeCertificate command (cmdlet).

Method #1: Output to the Screen

Open Exchange Management Shell
Run the following command:

-> New-ExchangeCertificate -GenerateRequest -SubjectName "C=GB, O=Comodo, cn=owa.comodo.com" -PrivateKeyExportable $true

Note: You can copy into notepad (or any text editor) and paste the command into the shell.
Alternatively, one can run the following command add the SANs(Subject Alternative Names) in the CSR as well. (optional)

-> New-ExchangeCertificate -GenerateRequest -SubjectName "C=GB, O=Comodo, cn=owa.comodo.com" -DomainName owa.comodo.com, owa, autodiscover.comodo.com -PrivateKeyExportable $true
CSR will be displayed on screen. You can copy and paste this information.

Method #2: Save to File

Open Exchange Management Shell
Run the following commands:

-> $CSR = New-ExchangeCertificate -GenerateRequest -SubjectName "C=GB, O=Comodo, cn=owa.comodo.com" -PrivateKeyExportable $true

-> Set-Content -Path "C:\2010certreq.txt" -Value $CSR
At the path location specified in the previous step, your CSR will be written to that file name you have provided.

For more information about the New-Exchange Certificate command(cmdlet), please visit Microsoft's TechNet.