IUpdate2::CopyToCache method (wuapi.h)

Copies files for an update from a specified source location to the internal Windows Update Agent (WUA) download cache.


HRESULT CopyToCache(
  [in] IStringCollection *pFiles


[in] pFiles

An IStringCollection interface that represents a collection of strings that contain the full paths of the files for an update.

The strings must give the full paths of the files that are being copied. The strings cannot give only the directory that contains the files.

Return value

Returns S_OK if successful. Otherwise, returns a COM or Windows error code.

This method can also return the following error codes.

Return code Description
This method cannot be called from a remote computer.
A parameter value is invalid.
The computer could not access the update site.


This method returns WU_E_INVALID_OPERATION if the object that is implementing the interface has been locked down.

Note  We don't recommend or support the use of the IUpdate::CopyFromCache and IUpdate2::CopyToCache methods to move downloaded updates from one computer to another computer. When the Windows Update Agent (WUA) downloads an update, it might only download the portions of the update’s payload that are necessary for a particular client computer. The necessary portions of the update’s payload can often vary from one computer to another computer, even if the computers have similar hardware and software configurations. IUpdate2::CopyToCache only works if the provided files are an exact match for the files that Windows Update would have normally downloaded on that computer; if you called IUpdate::CopyFromCache to obtain the files on a different computer, the files are likely not to match the files that Windows Update would have normally downloaded so IUpdate2::CopyToCache might fail.


Minimum supported client Windows XP, Windows 2000 Professional with SP3 [desktop apps only]
Minimum supported server Windows Server 2003, Windows 2000 Server with SP3 [desktop apps only]
Target Platform Windows
Header wuapi.h
Library Wuguid.lib
DLL Wuapi.dll

See also