ERROR_INSTALL_TRANSFORM_REJECTED - 1644 (0x66C)
One or more customizations are not permitted by software restriction policy.
Updated: Feb 21, 2026
Technical Meaning
The error code ERROR_INSTALL_TRANSFORM_REJECTED with the numeric value of 1644 and the hexadecimal representation of 0x66C is returned when a customization or transformation attempt during an installation process is denied by software restriction policies.
Error Details
This error typically occurs in scenarios where customizations are applied to installed components, such as modifying registry entries, patching files, or altering configuration settings. The policy that restricts these actions can be enforced through various mechanisms, including Group Policy Objects (GPO), Software Restriction Policies (SRP), and other security policies.
Usage Context
The error is commonly encountered in the context of software installations where custom modifications are attempted. It may also appear during patching or update processes that involve altering system files or registry keys.
Developer Interpretation
When this error code is returned, it indicates that a specific customization attempt has been blocked by an active security policy. Developers should ensure that any changes made to the system during installation are compliant with the current software restriction policies. This can be achieved by either modifying the policy settings or ensuring that the customizations being applied do not violate existing restrictions.
Related Errors
ERROR_INSTALL_FAILURE(1603, 0x64F): A generic failure occurred during installation.ERROR_INSTALL_PACKAGE_INVALID(1625, 0x679): The package is invalid or corrupted and cannot be installed.
FAQ
Q: What does the error code ERROR_INSTALL_TRANSFORM_REJECTED signify?
A: It indicates that a customization attempt during installation has been denied by software restriction policies.
Q: How can I resolve this issue?
A: Review the current security policies and ensure that any customizations are compliant. Adjusting policy settings or modifying the customization process may be necessary to avoid this error.
Summary
The ERROR_INSTALL_TRANSFORM_REJECTED error code is a specific indication of a policy violation during an installation process. Developers should understand the context in which this error occurs and ensure that their customizations are compliant with existing security policies.