Internet Information Services IIS8 and 8.5
How to create a CSR on Windows 2012 – IIS 8 and Windows 2012 R2 – IIS 8.5
From the Start screen, click or search for Internet Information Services (IIS) Manager and open it.
Click on the server name.
From the center menu, double-click the "Server Certificates button" in the "IIS" section (it is in the middle of the menu).
From the Actions menu, click Create Certificate Request.
Fill in information in Request Certificate wizard and click Next.
Choose Cryptographic Service provider and Key length and click Next.
Save request file.