Event Logs

Writing to Windows event log is quite easily achieved:

using System.Diagnostics;

...

// Create the source, if it does not already exist.
if(!EventLog.SourceExists("MySource")){
EventLog.CreateEventSource("MySource", "MyNewLog");
Console.WriteLine("CreatingEventSource");
}

// Create an EventLog instance and assign its source.
EventLog myLog = new EventLog();
myLog.Source = "MySource";

// Write an informational entry to the event log.
myLog.WriteEntry("Writing to event log.");

More info here:
http://msdn.microsoft.com/en-us/library/system.diagnostics.eventlog(VS.80).aspx