Normally, when creating a windows service in .NET you use an ServiceInstaller to install the service. The ServiceInstaller contains a property named StartType (http://msdn2.microsoft.com/en-us/library/system.serviceprocess.serviceinstaller.starttype(v s.80).aspx). You can set this property to one of the ServiceStartMode values (http://msdn2.microsoft.com/en-us/library/system.serviceprocess.servicestartmode(VS.80).aspx ).
So in your case, you need to set it to Automatic which indicates that the service needs to be started automatically.
Hope this helps.
Greetz,
Geert
http://geertverhoeven.blogspot.com