Windows Error Reporting is a 'free' service from Microsoft that integrates into your product and allows end-users to report detailed error information to Microsoft. Microsoft then passes this information on to the vendor (you) in the form of mini-dumps and error reports that can then be debugged inside of Visual Studio and/or WinDbg. This seems like an invaluable service to an ISV that runs their products on Windows. For WinForm applications, there is a dialog that appears that allows the user to click 'Send Error Report'. I would hope there is also a way to automate the error reporting as there could be no user interface to the product (e.g., Windows Services).

The kicker to WER is that you need to have a digital certificate which is not cheap. However, depending upon the breadth of your customer base, it may be well worth it.