How to track when my application has unexpectedly shut down?

Question

I'm writing an application whose purpose involves a lot of logging of different events. Among those I would also like to have an event that the application was shut down - even if unexpectedly like because of a power loss.

Naturally, when the power goes out I don't get a chance to write anything anywhere. So my idea was to continuously write a timestamp in some known location (say, once per minute), and when the application was next run, it could determine the approximate time of the unexpected shutdown. A precision of 1 minute would be acceptable for me.

However I'm worried that caching at the OS and disk level might interfere with this approach. Is there a better way or if not - how to make sure that the data I just wrote is REALLY written out to the physical medium?

Added: Oh, almost forgot the buzzword line: Windows XP and above; .NET 3.5; C#.

Answer 1

Edit: removed the incorrect answer (due to not reading the question properly)

You could use the FlushFileBuffers method, but that will still only write it to the device, you still can't get the actual drive to write it (as far as I know).
http://www.pinvoke.net/default.aspx/kernel32/FlushFileBuffers.html?diff=y

Answer 2

Unexpected shutdowns are logged in the system event log.

When your application shuts down cleanly, write it to your logfile. Next time your application starts check if your application was shut down the way it supposed to, otherwise check the system event log.