There is only OpenAL32.dll, and since this isn't my computer, will moving the dll file to a backup folder work?This is most likely caused by an OpenAL version not matching the version the game was compiled to.
Try this:
Go to C:\Windows\system32\
and check if OpenAL32.dll and OpenAL64.dll are present,
if they are, delete them
Now sound should be fine.
- Andy