A good alternative fix (failing the success of the above) is to affect a Windows repair. With Windows Vista this process is slightly different than that of previous versions.
You will require your Windows Vista installation DVD, as well as a copy of the following instructions.
Note that reverting to a previous System Restore point is not likely to resolve this issue. Also note that users with Windows restore discs will not be able to perform the following steps.
First, insert the Windows Vista DVD, and reboot your PC. Allow the system to boot from the DVD, and in the resulting console, select the System Repair option.
Following this, on the Setup screen, using the arrows on your keyboard choose Repair Computer.
You will then be asked to select your installation of Windows. (If you have multiple operating systems installed, you should be aware of which one is which at this stage. If not, you may need to boot back into Windows in order to identify the troublesome installation.)
With your correct installation of Windows selected, choose Startup Repair, and follow the on-screen instructions. Once completed, the issue should be resolved – no more Windows Audio Endpoint Builder error!