About the way to take Windows Services

I'm an intermediate C# programmer and I'm getting ready for Exam 70-536, my question is where I can find a good example about windows services built in .net platform.

If you already done windows开发者_JS百科 services ... can you tell me about your service?

What would be a clear example that I should do to get this topic right.

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This is a good tutorial to start with windows services : http://www.codeproject.com/KB/system/WindowsService.aspx