RegistrationServices.UnregisterAssembly Method

Unregisters the classes in a managed assembly.

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

public virtual bool UnregisterAssembly (
	Assembly assembly
public boolean UnregisterAssembly (
	Assembly assembly
public function UnregisterAssembly (
	assembly : Assembly
) : boolean
Not applicable.



The assembly to be unregistered.

Return Value

true if assembly contains types that were successfully unregistered; otherwise false if the assembly contains no eligible types.

Exception typeCondition


assembly is a null reference (Nothing in Visual Basic).


The full name of assembly is a null reference (Nothing in Visual Basic).


A method marked with ComUnregisterFunctionAttribute is not static.


There is more than one method marked with ComUnregisterFunctionAttribute at a given level of the hierarchy.


The signature of the method marked with ComUnregisterFunctionAttribute is not valid.


A user-defined custom unregistration function (marked with the ComUnregisterFunctionAttribute attribute) throws an exception.

UnregisterAssembly removes the registry entries for the types in the specified assembly previously added by RegisterAssembly. This method also calls any unregistration functions found in the assembly.

  • SecurityAction.LinkDemand  for permission to call unmanaged code. Associated enumeration: UnmanagedCode Security action: LinkDemand.

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0