CorBindToRuntime Function

Enables unmanaged hosts to load the common language runtime (CLR) into a process.

This function has been deprecated in the .NET Framework 4.


HRESULT CorBindToRuntime (  
    [in]  LPCWSTR     pwszVersion,
    [in]  LPCWSTR     pwszBuildFlavor,
    [in]  REFCLSID    rclsid,
    [in]  REFIID      riid,
    [out] LPVOID FAR  *ppv  


[in] A string describing the version of the CLR you want to load.

A version number in the .NET Framework consists of four parts separated by periods: The string passed as pwszVersion must start with the character "v" followed by the first three parts of the version number (for example, "v1.0.1529").

Some versions of the CLR are installed with a policy statement that specifies compatibility with previous versions of the CLR. By default, the startup shim evaluates pwszVersion against policy statements and loads the latest version of the runtime that is compatible with the version being requested. A host can force the shim to skip policy evaluation and load the exact version specified in pwszVersion by passing a value of STARTUP_LOADER_SAFEMODE for the flags parameter, as described below.

If the caller specifies null for pwszVersion, the latest version of the runtime is loaded. Passing null gives the host no control over which version of the runtime is loaded. Although this approach may be appropriate in some scenarios, it is strongly recommended that the host supply a specific version to load.

[in] A string that specifies whether to load the server or the workstation build of the CLR. Valid values are svr and wks. The server build is optimized to take advantage of multiple processors for garbage collections, and the workstation build is optimized for client applications running on a single-processor machine.

If pwszBuildFlavor is set to null, the workstation build is loaded. When running on a single-processor machine, the workstation build is always loaded, even if pwszBuildFlavor is set to svr. However, if pwszBuildFlavor is set to svr and concurrent garbage collection is specified (see the description of the flags parameter), the server build is loaded.

[in] The CLSID of the coclass that implements either the ICorRuntimeHost or the ICLRRuntimeHost interface. Supported values are CLSID_CorRuntimeHost or CLSID_CLRRuntimeHost.

[in] The IID of the requested interface from rclsid. Supported values are IID_ICorRuntimeHost or IID_ICLRRuntimeHost.

[out] The returned interface pointer to riid.


If pwszVersion specifies a runtime version that does not exist, CorBindToRuntimeEx returns an HRESULT value of CLR_E_SHIM_RUNTIMELOAD.

CorBindToRuntimeEx and CorBindToRuntime perform the same operation, but the CorBindToRuntimeEx function allows you to set flags to specify the behavior of the CLR.

Execution Context and Flow of Windows Identity

In version 1 of the CLR, the WindowsIdentity object does not flow across asynchronous points such as new threads, thread pools, or timer callbacks. In version 2.0 of the CLR, an ExecutionContext object wraps some information about the currently executing thread and flows it across any asynchronous point, but not across application domain boundaries. Similarly, the WindowsIdentity object also flows across any asynchronous point. Therefore, the current impersonation on the thread, if any, flows too.

You can alter the flow in two ways:

  1. By modifying the ExecutionContext settings to suppress the flow on a per-thread basis (see the SuppressFlow, SuppressFlow, and SuppressFlowWindowsIdentity methods).

  2. By changing the process default mode to the version 1 compatibility mode, where the WindowsIdentity object does not flow across any asynchronous point, regardless of the ExecutionContext settings on the current thread. How you change the default mode depends on whether you use a managed executable or an unmanaged hosting interface to load the CLR:

    1. For managed executables, you must set the enabled attribute of the <legacyImpersonationPolicy> element to true.

    2. For unmanaged hosting interfaces, set the STARTUP_LEGACY_IMPERSONATION flag in the flags parameter when calling the CorBindToRuntimeEx function.

    The version 1 compatibility mode applies to the entire process and to all the application domains in the process.


Platforms: See System Requirements.

Header: MSCorEE.h

Library: MSCorEE.dll

.NET Framework Versions: Available since 1.0

See also