In T122617#1563842, @BISWizard wrote:

Hello guys,
copy the file XAPOFX1_5.dll

• from Jun2010_XAudio_x86.cab to C:\Windows\SysWOW64\
• from Jun2010_XAudio_x64.cab to C:\Windows\System32\
  
  Don't let Windows to fools you. If 32-bit game says it's loading something from 'C:\Windows\System32' it is most likely loading it in 'C:\Windows\SysWOW64' (system silently redirects the file path), so the paths above are really correct. Btw: I'd recommend you to use Windows Explorer to do this, as other tools might run into the same issue with folder re-direction.

Same Problem since I first started playing o_O