Unattended installation

Hi 

We are working on an AVEVA migration project which requires unattended installation of the applications. However it fails as Manual says:

execute the following at the command line using the System Centre Configuration Manager

eg "msiexec /i "file location"\setup.msi /quiet INSTALLLEVEL=6" But there is no such file named setup,msi, instead setup.exe. 

We are doing via powershell. Is there any solution you can suggest please?

Thanks in advance.