FileSystemWatcher relies on the operating system to enhance the event. If there is no OS on the storage device, there is no OS to raise the level of events.
Note that some factors can affect which file system change events are raised, as described in the following:
General file system actions can lead to several events. For example, when a file moves from one directory to another, several OnChanged events and some OnCreated and OnDeleted events can be raised. Moving a file is a complex operation consisting of several simple operations, so several events occur. Similarly, some applications (such as antivirus software) may trigger additional file system events that are detected by FileSystemWatcher.
FileSystemWatcher can browse drives until they are switched or deleted. FileSystemWatcher does not generate events for CDs or DVDs because timestamps and properties cannot be changed. Remote computers must have one of the necessary platforms installed for the component to work properly.
If multiple FileSystemWatcher objects are viewing the same UNC path in Windows XP before Service Pack 1 (SP1) or Windows 2000 Service Pack 2 (SP2) or earlier, then only one of the objects fires an event. On computers running Windows XP Service Pack 1 (SP1) and later, Windows 2000 SP3 or later, or Windows Server 2003, all FileSystemWatcher objects will raise the corresponding events.
Setting the Filter property does not reduce what is included in the buffer.
Please note that FileSystemWatcher does not cause an error event when the event is skipped or when the buffer size is exceeded due to dependencies with the Windows operating system. To not skip events, follow these guidelines:
Increasing the buffer size using the InternalBufferSize property can prevent the absence of file system change events.
Avoid viewing files with long file names. Consider renaming using shorter names.
Keep your event handling code as short as possible.