Mailbag: Why doesn't the green button on my remote work until I launch Media Center manually?

Question:

I have a computer that is running Windows XP Media Center Edition 2005.  When I press the green button on my Media Center remote control, it will not launch Media Center for me.   I can use the mouse to launch Media enter, and after that the remote control will work fine.  Even if I close Media Center, I can re-open it by using the green button on my remote control once I have launched Media Center at least once.  However, if I reboot my computer, the same thing happens again.

Why is my system acting like this, and is there a way I can fix it so that the green button on my remote control will work all the time without needing to start Media Center manually with the mouse the first time?

Answer:

There is an application named ehTray that normally runs in the background on a Windows Media Center PC that listens for the green button on the remote to let you start Media Center.  By default, when installing Windows XP Media Center Edition, the ehTray application is configured to start each time Windows starts.  In addition, if it is not running when you start Media Center for the first time, Media Center will launch it for you.

It sounds like the registry entry to start that service when Windows starts was removed from this system.  The following steps can be used to create a registry value that will cause the ehTray application to run each time Windows is started so that the green button on a Media Center remote control will work without needing to first launch Media Center manually:

  1. Click on the Start menu, choose Run, type cmd and click OK 
  2. Run this command:  reg add "HKLM\Software\Microsoft\Windows\CurrentVersion\Run" /v ehTray.exe /t REG_SZ /d c:\windows\ehome\ehtray.exe /f 
  3. Reboot 
  4. Try to use your remote control to launch Media Center

Note: On Windows Vista, the configuration of the ehTray application has changed a little bit.  The registry setting to automatically start ehTray when Windows starts is located under HKEY_CURRENT_USER instead of HKEY_LOCAL_MACHINE, and it will not appear by default when you install Windows Vista.  However, the green button on a Media Center remote will work correctly on a default install of Windows Vista Home Premium or Ultimate editions, even if you have not yet launched Media Center for the first time.

<update date="9/4/2007"> Updated the not about Windows Vista behavior because I misunderstood the behavior on a newly installed OS. Thanks to Fu for pointing this out to me. </update>