Hi nadia,
After you build your exe right click on your exe and select Explore you will land on your build page there you will find a folder named Data. Just copy the lvsound.dll in the particular folder. when you copy the exe to another system copy the entire build folder and run the exe. the issue will be solved.
Kudos are Welcome 😄

Certified LabVIEW Developer
Best LabVIEW Programmer @NIDAYS 2015