Windows 7 MSI Fix tintag add HKCU Healing Action

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Tinytag explorer for whatever reason thought it best the user should need to enter the registration code, rather than it being part of the machine via HKLM, helpful.

I use this as an example of how to use an advertised shortcut to 'heal' the code into the HKCU when the shortcut is clicked on.

i.e. you will get the Windows installer pop up when a new user first clicks on the shortcut to start the program.

MSI Healing

Registry Table

This adds the software's activation code to the HKCU (Root 1), the Primary Key [Registry column] is called 'code' (See Component table)

Registry table

Component table

A new Component is added called 'code' with a randomly made ComponentID 'some random GUID', Attribute '0x004', KeyPath 'code' [ = Primary Key in registry table called 'code' ]

  • Attribute bit flag 0x004 = KeyPath is in the registry table (msidbComponentAttributesRegistryKeyPath)
Component table

FeatureComponents table

This just creates a new Feature called 'CurrentUser' with a Component called 'code'

FeatureComponents table

Feature table

A new Feature is created called 'CurrentUser' which is the new root (null Feature_Parent)

The original entry Feature 'Product' is changed to no longer be the root and instead be a sub-feature under the Feature CurrentUser (the Feature_Parent)

Feature table
  • Having only HKCU keys makes it not need source MSI or admin/install permissions to heal

Shortcut table

aka the 'Entry Point' or 'Advertised' feature. This is unchanged.

  • Note the Feature this is part of (Target) is called 'Product'. (See Feature table).
Shortcut table


How it works

Entry point is triggered (The desktop shortcut), this makes the MSI enumerate the Feature this shortcut is in which is 'Product'. Then it checks its parent Feature called 'CurrentUser'. The primary key of each component is checked within these to make sure it exists. When it gets to the component 'code' it will see the keypath of this pointing to the Registry Table (Primary Key) [also called] 'code'], which is a HKCU, doesn't exist, and thus create it.

  • If it finds one thing missing it will fix the whole Feature, not just the missing bit. Thus separating the HKCU bits to their own Feature (CurrentUser) makes healing that alone quick.


Misc Fixes

InstallExecuteSequence table

This contained two fixes for tinytag (unrelated to the HKCU healing);

  • silent install ignored the target path change and caused a silent install to dump everything to the root of C !
  • remove the pointless reboot action
InstallExecuteSequence table

Links

For a more in depth explantion but without a pictoral example this is well worth a read

and this slightly more terse version

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