If you are using windows, the windows Installer will create a service for IHS and Admin Service.

If you chose not to do this at install time it is possible to do it post install using the following commands:

httpd -k install -n <name of service> -f <path to config file>
httpd -k install -n IBMHTTPAdmin -f E:\IBM\HTTPServer\conf\admin.conf
httpd -k install -n IBMHTTP -f E:\IBM\HTTPServer\conf\httpd.conf