I use a routine that can start and stop services via Delphi but I also need to be able to disable them, is it possible?
Besides using the previous methods, if you need more control you can use WMI.
With Win32_Service class have access to all information of the services installed on the machine and you can has access to methods: Start, Stop, Pause, Resume, Interrogate, Create, Delete, Change, ChangeStartMode...
Here (Web / SourceForge)you can find a set of components to work with WMI (GLibWMI components Library); There are one called CServiceInfo thah give you all information and some methods of this class.
In addition with the package tere are some demos; One is called (ServiceControl) and implement all methods.
All the package are source included. See the code it can be usefull for you.
Regards.