In Windows Vista 64-bit, Microsoft, the integrated Windows Media Player 11 comes in both versions of 32-bit and 64-bit. However, the default Windows Media Player 11 has been set to the 32-bit edition. Due to compatibility issues, the 64-bit Windows Media Player 11 is left in the background.

This happens because codecs and DirectShow add-ons have been designed with the 32-bit edition of Windows Media Player 11. With the support for the 64-bit platform gaining increased consistency and codecs being released with full compatibility with x64 WMP 11, you might want to set the 64-bit version of Windows Media Player 11 as the default application.

 
Windows Media Player 11 x86

First off, “%Programfiles(x86)%Windows Media Player” and “%Programfiles%Windows Media Player” are the two standard locations for the 32-bit WMP 11 x86 and the x64 WMP 11 respectively. In this context, launching the application from the right location, or creating a shortcut will enable you to use either of the Windows Media Player 11 versions on x64 Vista. “%Programfiles%Windows Media Playerwmplayer.exe” is the actual patch that will execute x64 WMP 11.

 
Windows Media Player 11 x64

Additionally, you can open an elevated command: prompt and enter “%Programfiles%Windows Media Playerwmplayer.exe.” Running the command with administrator privileges is mandatory. Following this initial step, you have to access the Registry Editor. Navigate your way to “HKEY_LOCAL_MACHINESOFTWAREMicrosoftWindowsCurrentVersionApp Pathswmplayer.exe” registry key.

Here, you will have to modify the Patch and Default registry subkeys. Make the first “%Programfiles(x86)%Windows Media Player” and the second “%ProgramFiles%Windows Media Playerwmplayer.exe.”

And you're done. At the end of this process, you have successfully swapped x86 WMP 11 with x64 WMP 11 on your 64-bit Windows Vista. To switch back to the 32-bit WMP 11, run “%windir%system32unregmp2.exe /SwapTo:32” from an elevated command prompt and reset the values of the Patch and Default subkeys.

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2. The Windows Vista 64-bit upgrade from Windows Marketplace requires a 64-bit operating system
3. Windows Vista Feature Focus: 64-Bit (x64) Support
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5. 64-bit Editions of Windows Vista
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7. Windows PowerShell 1.0 Installation Package for Windows Vista x64 Edition (KB928439)