An MST-file contains transforms to be applied to a MSI file.
A transform is usually a small configuration change.
This is typically used to apply local configuration settings, for example to disable the automatic update feature of a software product.
Creating a transform file is an alternative to modifying a MSI-file. Both can be done for example with Orca.
MST-files are being applied by Windows Installer while it
is installing an MSI-file. This is done with a command like this:
msiexec /qb /i AdbeRdr1010_de_DE.msi TRANSFORMS=AdbeRdr1010_de_DE.mst
In Group Policy Objects they are deployed together with the MSI file to that they belong. If an MST-file is later added to a MSI-file, or if the MST-file was modified, then the MSI-file must be redeployed.
last update: 11-Jan-2012