File used by Microsoft PlayReady, a Digital Rights Management (DRM) program used for streaming online video; named mspr.hds (Microsoft PlayReady HDS file) and stored in the C:\ProgramData\Microsoft\PlayReady\ directory in Windows or /Library/Application Support/Microsoft/PlayReady/ in Mac OS X.
HDS files are most commonly encountered when upgrading Microsoft Silverlight software, which can cause Netflix streaming to malfunction. Many users have successfully fixed this issue by shutting down all programs, deleting mspr.hds or renaming it to mspr.hds.bak, and then restarting Netflix. Upon restart, Netflix will create a new copy of the mspr.hds file, which fixes the streaming problem.
Partial or whole hard disk created by Parallels Desktop virtualization software; stores the contents of a virtual machine's hard drive and is mounted by Parallels when the VM is opened; can be one of multiple HDS files that comprise the total hard drive; located within a .HDD hard drive file, which itself is saved inside the .PVM VM file.
To view the files within an HDS file, you must mount its enclosing HDD file with Parallels Mounter, a program included with Parallels Desktop. You can accomplish this by following these instructions:
Open the associated PVM file by right-clicking it and choosing "Show Package Contents."
Locate the main HDD file for the VM (has the same filename previx as the PVM file).
Right-click the HDD file and choose Open With → Parallels Mounter.app.
If you do not see Parallels Mounter.app in the list of programs to open the HDD file with, you can find it located in the /Library/Parallels/ directory on your hard drive.