windows installer - Applying an updated MST to an msi for REINSTALL? -

i have created in past msi have used deploy application.

now, want distribute new update of product mst msi (since have changed msi , want transformation applied). problem transform file applied on new installations, seems not applied on installed places.

in order fix this, way have found going hklm\software\classes\installer\<gid> , add mst there in transform key. requires lot of manual work, finding actual productcode add key to, copying mst somewhere permanent, etc. can think on other way done?

what's update product? if build major upgrade apply new transform when install new upgrade msi file.

you shouldn't expect hack system enough think there's transform present isn't! far easier change 1 file in product , create patch include changes in transform 1 new file. patch isn't new file - it's changes between 2 msi files, , doing safer , more reliable.