The IMAPIFormMgr::PrepareForm method downloads a form for launching.
HRESULT PrepareForm(
ULONG ulUIParam,
ULONG ulFlags,
LPMAPIFORMINFO pfrmiInfo
);
Form viewers call the IMAPIFormMgr::PrepareForm method to download a form from a form container for launching. Most form viewers do not need to call PrepareForm because both the IMAPIFormMgr::CreateForm and IMAPIFormMgr::LoadForm methods call PrepareForm if necessary.
PrepareForm can be used to obtain the dynamic-link libraries (DLLs) and other files associated with a form in order to modify them. If the modified form is loaded back into its form container, it must be reinstalled.
IMAPIFormMgr::CreateForm, IMAPIFormMgr::LoadForm