Index: trunk/eraser6/Eraser.DefaultPlugins/FileSystems/Windows.cs
===================================================================
--- trunk/eraser6/Eraser.DefaultPlugins/FileSystems/Windows.cs	(revision 1863)
+++ trunk/eraser6/Eraser.DefaultPlugins/FileSystems/Windows.cs	(revision 1866)
@@ -76,7 +76,17 @@
 				return;
 
-			//Set the date of the file to be invalid to prevent forensic
-			//detection
-			info.Attributes = FileAttributes.NotContentIndexed;
+			//Reset the file attributes to non-content indexed so indexing
+			//services will not lock the file.
+			try
+			{
+				info.Attributes = FileAttributes.NotContentIndexed;
+			}
+			catch (ArgumentException e)
+			{
+				//This is an undocumented exception: when the path we are setting
+				//cannot be accessed (ERROR_ACCESS_DENIED is returned) an
+				//ArgumentException is raised (no idea why!)
+				throw new UnauthorizedAccessException(e.Message, e);
+			}
 
 			//Rename the file a few times to erase the entry from the file system