What is the HDS file format?
Files with the extension .hds belong to the category of DRM (Digital Rights Management) files. Specifically, an .hds file is the local license store - a Hashed Data Store - used by Windows Media DRM and Microsoft PlayReady to hold all digital licenses issued to a particular device.
The content of .hds files consists of encrypted information that controls the playback ability of protected multimedia resources for specific recipients. When a user purchases or licenses protected content - on a platform such as Netflix or through Windows Media Player - the rights details are recorded in this local store so the content can play on that device. Playback is tied to the device's identity, meaning .hds files cannot be transferred between machines. Users who have purchased access can play protected media only on defined devices; this information is stored precisely in files with the .hds extension.
The default location is %LOCALAPPDATA%\Microsoft\Windows Media\DRM\ or %PROGRAMDATA%\Microsoft\PlayReady\. Microsoft explicitly recommends against deleting .hds files: doing so requires re-acquiring all previously issued DRM licenses, and some licenses may no longer be available for re-download. If corrupted, access to previously licensed content may be permanently lost.
The .hds store grows automatically as more licenses are acquired and is managed by Windows with no user interface. It is a machine-specific encrypted database - not to be confused with the protected .wmv or .wma content files themselves.
Security & safety
RISK: LOWThe HDS file itself poses no security risk - it is an encrypted DRM license database, not executable content. However, do not delete it without understanding the consequence (loss of purchased DRM licenses). If found in an unexpected location, it may indicate a DRM-enabled application installed silently - investigate the parent application.
Format details
in a nutshell- Adobe HTTP Dynamic Streaming segment file - Adobe HDS (HTTP Dynamic Streaming) uses .f4f segment files sometimes associated with .hds manifests; unrelated to Microsoft DRM.
Programs that open HDS files
Windows3 apps
Microsoft PlayReady
Built-in PlayReady runtime reads/writes HDS automatically per-application context. 
Windows Media Player
Built-in WMP manages DRM license acquisition automatically. If licenses are lost, use WMP's license management tools or re-download content.
Microsoft Windows (automatic)
Built-in HDS is managed automatically by the DRM runtime. Do not open manually. Technical details
deep spec| Format type | Proprietary encrypted binary DRM license database |
| Encoding | Binary, little-endian |
| Encryption | Proprietary; tied to machine/device identity (individualization) |
| Default location | %LOCALAPPDATA%\Microsoft\Windows Media\DRM\ or %PROGRAMDATA%\Microsoft\PlayReady\ |
| Typical file size | 1 KB - 10 MB (grows as more licenses are acquired) |
| Content | All Windows Media DRM licenses issued to the device, individualization data, and PlayReady persistent session data |
| DRM versions covered | Windows Media DRM v7, v9, v10; Microsoft PlayReady 1.x-4.x |
| Device binding | Machine-specific; cannot be transferred between devices |
| Integrity verification | Internal hash verification (opaque to end users) |
| Deletion risk | Deleting forces re-acquisition of all DRM licenses; some may be permanently unavailable |
| Custom store path | PlayReady API allows applications to specify a custom .hds license store location |
| Management | Automatic - managed by Windows and PlayReady runtime; no user-accessible interface |
| Released | circa 2003 (Windows Media DRM 7/9) |
| Latest version | Used by Windows Media DRM and Microsoft PlayReady (current) |
| Specification | learn.microsoft.com |
HDS conversions
Community Q&A
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