Unsecured Transforms
Transforms that have not been secured as described in Secured Transforms are unsecured transforms by default.
To apply an unsecured transform when installing a package, pass the transform file names in the TRANSFORMS property or command line string. Do not begin the string with the @ or | characters or set the TransformsSecure policy or the TRANSFORMSSECURE property. Note that you cannot combine unsecured transforms and secured transforms in the same transforms list.
If the package is installed or advertised in the per-user installation context, and has unsecured transforms, the installer saves the transform source in the Application Data folder in the user's profile. This enables a user to maintain their customization of a product while moving between computers.
If the package is installed or advertised in the per-machine installation context, and uses unsecured transforms, the installer saves the transform source in the %windir%\Installer folder.
During a first-time installation of the package, the installer first searches for the transform at the source supplied by the TRANSFORMS property or command line string. If this source is unavailable, the installer then searches for the transform at the source of the package next to the .msi file.
During a maintenance installation, the installer searches for the transform at the cache location. If the cached copy of the transform becomes unavailable, the installer searches for the transform at the source of the package next to the .msi file.
For more information, see Applying Transforms and Source Resiliency.