Install Windows Vista SP1 from Windows Update

Apparently there is a registry hack that will allow you to download the RTM bits of the first Service Pack for Windows Vista through the Windows Update.

Copy and paste this in a .cmd file and run it (use at your own risk):

@echo off

reg delete HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\VistaSp1 /f > NUL 2>&1
reg delete HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Windows\CurrentVersion\WindowsUpdate\VistaSP1 /f > NUL 2>&1

reg add HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\VistaSp1 /v Beta1 /t REG_SZ /d dcf99ef8-d784-414e-b411-81a910d2761d /f
IF NOT %errorlevel% == 0 ( goto ERROR)

:SUCCESS
@echo.
echo ===========================================================
echo  Windows Vista SP1 registry key has been set successfully.
echo  Please check for updates in Windows Update.
echo ===========================================================
@echo.
goto END

:ERROR
@echo.
echo ===========================================================
echo  FAILED to set Windows Vista SP1 registry keys.
echo  Please run this script by right clicking and selecting
echo  "Run as Administrator".
echo ===========================================================
@echo.
goto END

:END
pause