I'm using WIX files to build an MSI package.
It work using an environment value
<Property Id="ProgramFilesDir" Value="$(env.ProgramFiles)" />
<Property Id="ProgramFilesDir" Value="X:\MyFolder\" />
You shouldn't be using your computer's paths, as no one guarantees, for example, that the target machine is going to have drive X at all. Instead use the built-in paths, like so: