Projected File System (ProjFS) programming guide

The Windows Projected File System (ProjFS) allows a user-mode application called a "provider" to project hierarchical data into the file system, making it appear as files and directories in the file system.

In this section

Topic Description
Provider Overview Conceptual overview of a provider application.
Cache State in the Virtualization Root Describes the different cache states a file or directory managed by the provider may have.
Enabling Windows Projected File System Describes how to enable the ProjFS optional component.
Virtualization Instance Lifecycle Overview of the lifecycle of a ProjFS virtualization instance.
Enumerating Files and Directories Describes how a ProjFS provider participates in directory enumeration.
Providing File Data Describes how a provider supplies placeholder info and file data.
File System Operation Notifications Describes how a provider can receive notifications of file system operations.
Handling View Changes Describes how to update the client view of a provider's backing store.
Asynchronous Callback Handling Describes how the provider can asynchronously service callbacks.
Windows Projected File System API Reference Reference information for the ProjFS programming interface.

Additional Resources

Topic Description
RegFS Sample A sample ProjFS provider that projects the Windows registry into the file system.