Registry key path for Windows media player

Question

I am trying to play a video in Windows media player through my code. The path is:

 C:\Program Files (x86)\Windows Media Player\wmplayer.exe

If I hardcode it,

      string filePath = System.IO.Path.Combine (Application.streamingAssetsPath, "Demo.mp4");
      Process proc = new Process();
      proc.StartInfo.FileName = @"C:\Program Files (x86)\Windows Media Player\wmplayer.exe";
        proc.StartInfo.Arguments = "\"" + filePath + "\"";
        proc.Start ();

I can play the video. But I want to use the path which is universal for all the machines. So after going through this link Programmatically detect if Windows Media Player is installed, I re-wrote my code to:

     private string makePath;
RegistryKey myKey;
     makePath = @"HKLM\Software\Microsoft\Active Setup\Installed Components\{22d6f312-b0f6-11d0-94ab-0080c74c7e95}";
     myKey = Registry.LocalMachine.OpenSubKey (makePath);

     IEnumerator Example ()
{
    if (myKey == null) {
        print ("No Windows Media Player Installed");
    } else {
        proc.StartInfo.FileName = makePath;
        proc.StartInfo.Arguments = "\"" + filePath + "\"";
        proc.Start ();
    }

and calling this function somewhere But then myKey appears to be null. Is the path correct which I have mentioned here or what have to be made in order to get the video played?

try to use the Environment.GetFolderPath and get the program files folder via the SpecialFolders enum. This will ensure that the path is always correct on the machine running the app since some can be 32 bit OS's and others 64 bit OS's. I also agree with @DavidHeffernan about letting the Shell decide which player to use. — Ahmed ilyas, Mar 11 '14 at 12:30

score 2 · Answer 1 · answered Mar 11 '14 at 12:31

The reason you cannot find that registry key is that you are running a 32 bit process on a 64 bit system. And so the registry redirector comes into play. The code will attempt to resolve the registry key under the Wow6432Node.

Solve the problem by using the RegistryView enumeration to specify that you want to look in the 64 bit view of the registry. Or run as a 64 bit process.

FWIW, it might just be simpler to let the shell decide (using the user's file associations) which program to use to play the video.

jiten · Answer 2 · 2014-03-11T12:51:09.897

On 64-bit Windows, portions of the registry entries are stored separately for 32-bit application and 64-bit applications and mapped into separate logical registry views using the registry redirector and registry reflection, because the 64-bit version of an application may use different registry keys and values than the 32-bit version.

Here is an example of how to access the 32-bit view of the registry. Specifies which registry view to target on a 64-bit operating system use RegistryView.

Use this

var view32 = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine,
                                     RegistryView.Registry32);
using (var clsid32 = view32.OpenSubKey(@"Software\Microsoft\Active Setup\Installed Components\{22d6f312-b0f6-11d0-94ab-0080c74c7e95\}", false))
{
  // actually accessing Wow6432Node 
}

This answer lacks an explanation of what is going on. It also uses HKCU rather than HKLM. — David Heffernan, Mar 11 '14 at 12:48

Registry key path for Windows media player

2 Answers2