---
page_type: sample
description: "A minifilter that demonstrates registration with the filter manager."
languages:
- cpp
products:
- windows
- windows-wdk
---

# NullFilter File System Minifilter Driver

The NullFilter minifilter is a sample minifilter that shows how to register a minifilter with the filter manager.

## Universal Windows Driver Compliant

This sample builds a Universal Windows Driver. It uses only APIs and DDIs that are included in OneCoreUAP.

## Design and Operation

The *NullFilter* minifilter is a simple minifilter that registers itself with the filter manager for no callback operations.

For more information on file system minifilter design, start with the [File System Minifilter Drivers](https://docs.microsoft.com/windows-hardware/drivers/ifs/file-system-minifilter-drivers) section in the Installable File Systems Design Guide.