Don't know how this one could slip by me - Windows Server 2003 Service Pack 1 (SP1) shipped a rather important update: you can run SSL in kernel mode (http.sys) instead of user mode. There are restrictions which are detailed here (most B2C SSL sites will do just fine), and the procedure to enable kernel-mode SSL shows how to get up and running in no time. Mostly you are only dealing with the registry key HKLM\System\CurrentControlSet\Services\HTTP\Parameters\EnableKernelSSL.