Here’s an error a customer of mine received recently when trying to play videos on Netflix.  The problem persisted in all web browsers installed (Internet Explorer, Firefox, and Chrome).  A quick search across the internet reveals a solution which works for most people:

Browse to C:\ProgramData\Microsoft\PlayReady on Vista/7 machines and C:\Documents and Settings\All Users\Application Data\Microsoft\PlayReady on XP machines.  Rename the file mspr.hds to something else, such as mspr.hds.old (the file is recreated automatically).

Unfortunately, in this case, this solution didn’t work.  Probing further, I discovered that this problem only began occurring following the installation of a recent Windows Update (KB2636927).  To correct the issue, I was forced to uninstall Microsoft Silverlight and then reinstall an older version of the plugin until the problem is resolved on this machine.  I also had to hide this particular Windows Update to prevent it from reinstalling automatically!

Normally this is unadvisable as plugin updates most frequently provide security fixes and enhancements to the user’s machine, but in this case, there seemed to be no other solution.

If you’re experiencing this problem and you’re having trouble locating an older version of Silverlight to use, let me know and I can provide the installer!