Running an .exe file synchronously

I need to launch an .exe file from a PowerShell script and wait for the execution to complete.
By the way, the .exe file is a setup file produced by Installshield.
My .ps1 file looks like:

write-host "I am going to install"
write-host "Installation terminated"

How can I force the message “Installation terminated” to appear only after mysetup.exe is complete?

Try using Start-Process. The return object gives you a method you can use to wait for the process to terminate.