Referencing the Update Services Assembly
Applies To: Windows Server Update Services
To use the WSUS API, you need to reference the Update Services Administration assembly, Microsoft.UpdateServices.Administration.dll. Before you can reference the assembly on Windows Server, you must install the WSUS server role. Before you can reference the assembly on a Windows Client, you must install the WSUS client, which is part of the Remote Server Administration Tools (RSAT).
You can download RSAT from the following lcoations:
Windows Vista x86 − Microsoft Remote Server Administration Tools for Windows Vista
The assembly can be found in either the %windir%\assembly folder, or the %Program Files%\Update Services\Api folder. If you are unable to use this location to reference the assembly in Microsoft Visual Studio, you will need to copy it to another location.