Service applications let you check for updates on a system or monitor system resources, without interrupting your work. While they can be difficult to create, Delphi makes it simple. This article explains how to create a simple Windows service application in Delphi, which you can build on and modify to suit your own needs.
Creating a Windows Service in Delphi - Installing/Uninstalling the Service (Page 4 of 5 )
To install the service: Click Start and select run, then type: PATHTOYOURSERVICE\yourservicename.exe /INSTALL then press OK.
If your service is located in a directory called service on the c drive, then type c:\service\yourservicename.exe. The same thing applies when you uninstall.
To uninstall: Click on Start and select run, then type: PATHTOYOURSERVICE\yourservicename.exe /UNINSTALL then press OK.
To check whether your service is running, open up the TASK Manager and look for the service name.
The service I created is called diskmonitor.exe. Here’s an example of my Task Manager showing the simple DiskMonitor.exe service:
So, as you can see, Delphi makes it very easy to create a service. Although my example is trivial, you can create very complicated applications. Just remember that the bigger your service application is, the more resources it will consume.
Delphi-Kylix 
Internet Access: Client Service
