Hello Vijay,
Indeed, when running a 64-bit package type on a x86 machine you will get the following error message:

- x64 package.png (19.08 KiB) Viewed 2645 times
You can read more about this in the
Advanced Installer Package Types article.
When you are in need of creating only one setup package for 32-bit and 64-bit versions of your driver installation files (INF, DLL, CAT, etc.) then you need to create a
mixed package type. This way, the package runs as a 32-bit package on 32-bit systems and as a 64-bit package on x64 systems.
The .MSI does not support mixed package type, thus the package type will be turned into an .EXE package type. The .EXE bootstrapper built by Advanced Installer is a 32 bit one, this contains the x86 and x64 MSI files as well as the files to be installed from the CAB. When launched the EXE checks for the operating system architecture and it launches the correct MSI.
For details, please check the
How do I install drivers in a mixed package? article.
Best regards,
Dan