If for some reason you’ve powered on and while Apache seems to be running OK, lighttp isn’t (for example phpMyAdmin isn’t working on localhost:10081/phpmyadmin) then you will need to start it manually. This is probably caused by a dirty restart, such as a power failure. On Mac OS X run this command…

sudo /usr/local/zend/bin/lighttpdctl.sh start

For Windows, I’m afraid I will have to find that out!