What is 0xC000038E

STATUS_DRIVER_FAILED_PRIOR_UNLOAD

STATUS_DRIVER_FAILED_PRIOR_UNLOAD (0xC000038E) can be returned from FltLoadFilter function used for loading intalable file system driver. The reason of the erron in that the minifilter driver could not be loaded because a previous version of the driver is still in memory.

File systems and minifilters

File systems in Windows are implemented as file system drivers working above the storage system.

Every system-supplied file system in Windows is designed to provide reliable data storage with varying features to meet the user's requirements. Standard file systems available in Windows include NTFS, ExFAT, UDF, and FAT32. A comparison of features for each of these file systems is shown in File System Functionality Comparison. Additionally, the Resilient File System (ReFS), available on Windows Server 2012 and later versions, offers scalable large volume support and the ability to detect and correct data corruption on disk.

Developing a new file system driver is almost always unnecessary, and requirements/specifications for new file system drivers are not predictable. To that end, this design guide does not cover file system development. If you do need to develop a new file system driver beyond those available in Windows, sample code is available as a model (see below).

File system filter drivers

A file system filter driver intercepts requests targeted at a file system or another file system filter driver. By intercepting the request before it reaches its intended target, the filter driver can extend or replace functionality provided by the original target of the request. Examples of filter drivers include:

• Anti-virus filters
• Backup agents
• Encryption products

Filter driver developers use the system-supplied Filter Manager, which provides a framework for developing filter drivers without having to manage all the complexities of file I/O. The Filter Manager simplifies the development of third-party filter drivers and solves many of the problems with the legacy filter driver model, such as the ability to control load order through an assigned altitude.

File system

In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data is easily isolated and identified. Taking its name from the way a paper-based data management system is named, each group of data is called a "file." The structure and logic rules used to manage the groups of data and their names is called a "file system."

There are many different kinds of file systems. Each one has different structure and logic, properties of speed, flexibility, security, size and more. Some file systems have been designed to be used for specific applications. For example, the ISO 9660 file system is designed specifically for optical discs.

File systems can be used on numerous different types of storage devices that use different kinds of media. As of 2019, hard disk drives have been key storage devices and are projected to remain so for the foreseeable future. Other kinds of media that are used include SSDs, magnetic tapes, and optical discs. In some cases, such as with tmpfs, the computer's main memory (random-access memory, RAM) is used to create a temporary file system for short-term use.

Some file systems are used on local data storage devices; others provide file access via a network protocol (for example, NFS, SMB, or 9P clients). Some file systems are "virtual", meaning that the supplied "files" (called virtual files) are computed on request (such as procfs and sysfs) or are merely a mapping into a different file system used as a backing store. The file system manages access to both the content of files and the metadata about those files. It is responsible for arranging storage space; reliability, efficiency, and tuning with regard to the physical storage medium are important design considerations.