MsiDeterminePatchSequenceA function

The MsiDeterminePatchSequence function takes a set of patch files, XML files, and XML blobs and determines the best sequence of application for the patches to a specified installed product. This function accounts for patches that have already been applied to the product and accounts for obsolete and superseded patches.


UINT MsiDeterminePatchSequenceA(
  LPCSTR                 szProductCode,
  LPCSTR                 szUserSid,
  DWORD                  cPatchInfo,



The product that is the target for the set of patches. The value must be the ProductCode GUID for the product.


Null-terminated string that specifies a security identifier (SID) of a user. This parameter restricts the context of enumeration for this user account. This parameter cannot be the special SID strings "S-1-1-0" (everyone) or "S-1-5-18" (local system). For the machine context dwContext is set to MSIINSTALLCONTEXT_MACHINE and szUserSid must be NULL. For the current user context szUserSid can be null and dwContext can be set to MSIINSTALLCONTEXT_USERMANAGED or MSIINSTALLCONTEXT_USERUNMANAGED.


Restricts the enumeration to a per-user-unmanaged, per-user-managed, or per-machine context. This parameter can be any one of the following values.

Type of context Meaning
Patches are considered for all per-user-managed installations of the product for the user specified by szUserSid. A null szUserSid with this context means the current user.
Patches are considered for all per-user-unmanaged installations for the user specified by szUserSid. A null szUserSid with this context means the current user.
Patches are considered for the per-machine installation. When dwContext is set to MSIINSTALLCONTEXT_MACHINE the szUserSid parameter must be null.


The number of patches in the array.


Pointer to an array of MSIPATCHSEQUENCEINFO structures.

Return Value

The MsiDeterminePatchSequence function returns the following values.

Value Meaning
The function failed in a manner not covered in the other error codes.
An argument is invalid.
No valid sequence could be found for the set of patches.
An installation package referenced by path cannot be opened.
The patches were successfully sorted.
The .msi file was not found.
The path to the .msi file was not found.
The XML patch data is invalid.
The installation package was invalid.
A user that is not an administrator attempted to call the function with a context of a different user.
The configuration data for a registered patch or product is invalid.
The ProductCode GUID specified is not registered.
Windows Installer version 3.0 is required to determine the best patch sequence. The function was called with szProductCode not yet installed with Windows Installer version 3.0.
This error can be returned if the function was called from a custom action or if MSXML 3.0 is not installed.
The specified patch is unknown.


Users that do not have administrator privileges can call this function only in their own or machine context. Users that are administrators can call it for other users.

If this function is called from a custom action it fails and returns ERROR_CALL_NOT_IMPLEMENTED. The function requires MSXML version 3.0 to process XML and returns ERROR_CALL_NOT_IMPLEMENTED if MSXML 3.0 is not installed.

The MsiDeterminePatchSequence function sets the uStatus and dwOrder members of each MSIPATCHSEQUENCEINFO structure pointed to by pPatchInfo. Each structure contains information about a particular patch.

If the function succeeds, the MSIPATCHSEQUENCEINFO structure of every patch that can be applied to the product returns with a uStatus of ERROR_SUCCESS and a dwOrder greater than or equal to zero. The values of dwOrder greater than or equal to zero indicate the best application sequence for the patches starting with zero.

If the function succeeds, patches excluded from the best patching sequence return a MSIPATCHSEQUENCEINFO structure with a dwOrder equal to -1. In these cases, a uStatus field of ERROR_SUCCESS indicates a patch that is obsolete or superseded for the product. A uStatus field of ERROR_PATCH_TARGET_NOT_FOUND indicates a patch that is inapplicable to the product.

If the function fails, the MSIPATCHSEQUENCEINFO structure for every patch returns a dwOrder equal to -1. In this case, the uStatus fields can contain errors with more information about individual patches. For example, ERROR_PATCH_NO_SEQUENCE is returned for patches that have circular sequencing information.


Minimum supported client Windows Installer 5.0 on Windows Server 2012, Windows 8, Windows Server 2008 R2 or Windows 7. Windows Installer 4.0 or Windows Installer 4.5 on Windows Server 2008 or Windows Vista. See the Windows Installer Run-Time Requirements for information about the minimum Windows service pack that is required by a Windows Installer version.
Target Platform Windows
Header msi.h
Library Msi.lib
DLL Msi.dll

See Also



Not Supported in Windows Installer 2.0 and earlier