Apply HKCU registries to all users

About

This is a custom predefined action created by the Master Packager team that applies HKEY_CURRENT_USER registries to all users during SYSTEM context installation.

The action works by writing HKCU registry keys into the ntuser.dat file of each user profile, including the default user. This ensures that any new user who logs into the machine will automatically receive these registry keys.

This approach allows applying per-user configuration even when the MSI is installed under SYSTEM context, which is commonly used in enterprise deployments.

When to use it?

Use this action when it is needed to apply per-user HKEY_CURRENT_USER (HKCU) registries to all users while the MSI is installed under SYSTEM context.

This is commonly required when application configuration is stored in HKCU registries and needs to be consistent across all users.

How to use it?

1. Open MSI/MST with Master Packager
2. Click on Custom Actions in left menu
3. Click on Predefined Actions tab
4. Click “Add New Predefined Action” and choose Apply HKCU registries to all users
5. Click Browse HKCU .REG File to import your registry entries from a .reg file, or click Edit to manually enter the registry data.

Format must be the following:

Windows Registry Editor Version 5.00
[HKEY\_CURRENT\_USER\Software\SomeKey]
“SomeValue”=“1”

6. Review your registry entries in the Registry Preview window to ensure they are correct.