This documentation is archived and is not being maintained.

DllNotFoundException Class

Updated: August 2008

The exception that is thrown when a DLL specified in a DLL import cannot be found.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public class DllNotFoundException : TypeLoadException

The DllNotFoundException is thrown when a dynamic link library defined by the DllImportAttribute attribute or a comparable language construct, such as the Visual Basic Declare statement, cannot be found. It is not thrown when the common language runtime is unable to load a .NET Framework assembly.

Note that the DllImportAttribute attribute can specify the path to the directory in which the DLL resides. If a path is not specified, Windows uses the search order described in Dynamic-Link Library Search Order.

DllNotFoundException uses the HRESULT COR_E_DLLNOTFOUND, which has the value 0x80131524.

For a list of initial property values for an instance of DllNotFoundException, see the DllNotFoundException constructors.


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5, 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 3.5, 2.0, 1.0




August 2008

Added remarks.

Content bug fix.