First, the important concept is that U can have more than one service running inside a process i.e. 2 or 3 services can share the same process. (Remember thats why we have 2 classes: ServiceProcessInstaller and ServiceInstaller)
So follow the following steps:
- Make a dummy service under the same process as Ur main service
- Start the dummy service and attach the debugger to the process
- Put a break-point in the OnStart() method of Ur main service.
- Then start Ur main service... The break point will be hit ....Yahooooo.....