Open a project in Visual Studio.
If there is no project, then create new project C# Windows Service (.NET Core, worker)...

On the project, right-click.
In the menu, click Publish.

Choose where we will compile the project:
• Azure (this is a remote server)
• Docker (this is a container used for testing)
• Folder (this means a folder on your computer)
• Profile (use old settings)

 
Select any folder. I compile and assemble the project into a folder:
D:/MyWorkerServiceCore1/publish

 
Click Publish to compile and build the project:

Here are the files created:

 
Run the file: MyWorkerServiceCore1.exe
We'll see:

 
Note!
We make publish the project, i.e. compile and build the project.
A exe file and other files have been created.
Now we will register the exe file in the system and run it as Windows Service...