As shown in Schema the basic file schema is:
<wix namepace="...">
<!-- describes the app being installed -->
<product>
<!-- describes the msi package of the product -->
<package/>
<!-- describes the cab's within the msi -->
<media/>
</product>
</wix>
The product tag is created with a unique id as follows:
<product Id="c2a7..."
Manufacturer="XAct Software Solutions, Inc."
Name="TheProduct"
Version="0.0.1"
UpgradeCode="d4e3...">
<Package InstallerVersion="200"
Compressed="yes"
Manufacturer="XAct Software Solutions, Inc."
Description="A wonderful app!"
Comments="..."
Platform="x86"
InstallerPriveleges="elevated"
InstallScope="perMachine"/>
Note:
P
roduct != Package