MsiSourceListClearAllExA function (msi.h)

The MsiSourceListClearAllEx function removes all the existing sources of a given source type for the specified product or patch instance. The patch registration is also removed if the sole source of the patch gets removed and if the patch is not installed as a new patch by any client in the same context. Specifying that MsiSourceListClearAllEx remove the current source for this product or patch forces the installer to search the source list for a source the next time a source is required.


UINT MsiSourceListClearAllExA(
  [in]           LPCSTR            szProductCodeOrPatchCode,
  [in, optional] LPCSTR            szUserSid,
  [in]           MSIINSTALLCONTEXT dwContext,
  [in]           DWORD             dwOptions


[in] szProductCodeOrPatchCode

The ProductCode or patch GUID of the product or patch. Use a null-terminated string. If the string is longer than 39 characters, the function fails and returns ERROR_INVALID_PARAMETER. This parameter cannot be NULL.

[in, optional] szUserSid

This parameter can be a string SID that specifies the user account that contains the product or patch. The SID is not validated or resolved. An incorrect SID can return ERROR_UNKNOWN_PRODUCT or ERROR_UNKNOWN_PATCH. When referencing a machine context, szUserSID must be NULL and dwContext must be MSIINSTALLCONTEXT_MACHINE. Using the machine SID ("S-1-5-18") returns ERROR_INVALID PARAMETER. When referencing the current user account, szUserSID can be NULL and dwContext can be MSIINSTALLCONTEXT_USERMANAGED or MSIINSTALLCONTEXT_USERUNMANAGED.

[in] dwContext

This parameter specifies the context of the product or patch instance. This parameter can contain one of the following values.

Type of context Meaning
The product or patch instance exists in the per-user-managed context.
The product or patch instance exists in the per-user-unmanaged context.
The product or patch instance exists in the per-machine context.

[in] dwOptions

The dwOptions value determines the interpretation of the szProductCodeOrPatchCode value and the type of sources to clear. This parameter must be a combination of one of the following MSISOURCETYPE_* constants and one of the following MSICODE_* constants.

Flag Meaning
The source is media.
The source is a network type.
The source is a URL type.
szProductCodeOrPatchCode is a patch code.
szProductCodeOrPatchCode is a product code.

Return value

Value Meaning
The user does not have the ability to add or move a source. Does not indicate whether the product or patch was found.
The configuration data is corrupt.
Cannot access the Windows Installer service.
An invalid parameter was passed to the function.
All sources of the specified type were removed.
The specified product is unknown.
The specified patch is unknown.
Unexpected internal failure.


Administrators can modify the installation of a product or patch instance that exists under the machine context or under their own per-user context (managed or unmanaged.) They can modify the installation of a product or patch instance that exists under any user's per-user-managed context. Administrators cannot modify another user's installation of a product or patch instance that exists under that other user's per-user-unmanaged context.

Non-administrators cannot modify the installation of a product or patch instance that exists under another user's per-user context (managed or unmanaged.) They can modify the installation of a product or patch instance that exists under their own per-user-unmanaged context. They can modify the installation of a product or patch instance under the machine context or their own per-user-managed context only if they are enabled to browse for a product or patch source. Users can be enabled to browse for sources by setting policy, for more information, see DisableBrowse, AllowLockdownBrowse, and AlwaysInstallElevated policies.


The msi.h header defines MsiSourceListClearAllEx as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.


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. Windows Installer 3.0 or later on Windows Server 2003 or Windows XP. 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