Steam is not a registered protocol

The error was most likely caused by a damaged or incorrect entry in the following Windows Registry key:

 /HKEY_CLASSES_ROOT/Steam/Shell/Open/Command/(Default)

(This registry key should reference the full path to your Steam.exe file in the Steam installation directory, followed by "%1" - for example: "C:\Program Files\Valve\Steam\Steam.exe" "%1")

This registry key may have been altered by a registry editor, a system restore tool, or by moving your Steam installation directory.

Updates to Steam Public have improved the internal error checking for this registry key - the issue should be resolved at this time. If you encounter a "steam:// is not a registered protocol" error, please see the instructions link below:

Run Steam Installation Again

To install over your existing Steam installation, download a new copy of the Steam installer from the link below:

Get Steam Now: http://www.steampowered.com/index.php?area=getsteamnow

Run the installation program and specify your new Steam installation folder (if this folder has been moved).