I've just installed my unattended copy of XP for the first time (without virtual pc) and was pretty certain that the registry tweaks would work, the line to execute them was at the end of my batch file just before the auto-shutdown code. The only thing i can think of that may have caused them not to install was the fact the folder the tweaks.reg file was in had spaces in its name (INSTALL\REGISTRY TWEAKS) could that be the cause? If so i've removed the spaces in the folder name now changing it to REGTWEAKS do you think this will solve the problem? I've included my batch file so whoever wants to can look over it just incase.

CLS
@echo off
ECHO.
ECHO.
ECHO.
ECHO  Copying Tools...
ECHO.
ECHO  Please Wait...
COPY "%systemdrive%\INSTALL\TOOLS\deluser.exe" "%systemroot%\"
COPY "%systemdrive%\INSTALL\TOOLS\psshutdown.exe" "%systemroot%\"
ECHO.
ECHO.
ECHO.
ECHO  Removing Unnecessary Files...
ECHO.
ECHO  Please Wait...
DEL "%systemroot%\Blue Lace 16.bmp"
DEL "%systemroot%\Coffee Bean.bmp"
DEL "%systemroot%\FeatherTexture.bmp"
DEL "%systemroot%\Gone Fishing.bmp"
DEL "%systemroot%\Greenstone.bmp"
DEL "%systemroot%\Prairie Wind.bmp"
DEL "%systemroot%\Rhododendron.bmp"
DEL "%systemroot%\River Sumida.bmp"
DEL "%systemroot%\Santa Fe Stucco.bmp"
DEL "%systemroot%\Soap Bubbles.bmp"
DEL "%systemroot%\Zapotec.bmp"
DEL "%systemroot%\Web\Wallpaper\Crystal.jpg"
DEL "%systemroot%\Web\Wallpaper\Friend.jpg"
DEL "%systemroot%\Web\Wallpaper\Home.jpg"
DEL "%systemroot%\Web\Wallpaper\Moon flower.jpg"
DEL "%systemroot%\Web\Wallpaper\Peace.jpg"
DEL "%systemroot%\Web\Wallpaper\Power.jpg"
DEL "%systemroot%\Web\Wallpaper\Purple flower.jpg"
DEL "%systemroot%\Web\Wallpaper\Radiance.jpg"
DEL "%systemroot%\Web\Wallpaper\Ripple.jpg"
DEL "%systemroot%\Web\Wallpaper\Stonehenge.jpg"
DEL "%systemroot%\Web\Wallpaper\Vortec space.jpg"
DEL "%systemroot%\Web\Wallpaper\Ascent.jpg"
DEL "%systemroot%\Web\Wallpaper\Autumn.jpg"
DEL "%systemroot%\Web\Wallpaper\Azul.jpg"
DEL "%systemroot%\Web\Wallpaper\Follow.jpg"
DEL "%systemroot%\Web\Wallpaper\Red moon desert.jpg"
DEL "%systemroot%\Web\Wallpaper\Tulips.jpg"
DEL "%systemroot%\Web\Wallpaper\Wind.jpg"
DEL "%systemdrive%\Documents and Settings\All Users\Start Menu\Windows Update.lnk"
DEL "%systemdrive%\Documents and Settings\All Users\Start Menu\Set Program Access and Defaults.lnk"
DEL "%systemdrive%\Documents and Settings\All Users\Start Menu\Windows Catalog.lnk"
DEL "%systemroot%\system32\dllcache\scrnsave.scr"
DEL "%systemroot%\system32\dllcache\ss3dfo.scr"
DEL "%systemroot%\system32\dllcache\ssbezier.scr"
DEL "%systemroot%\system32\dllcache\ssflwbox.scr"
DEL "%systemroot%\system32\dllcache\ssmarque.scr"
DEL "%systemroot%\system32\dllcache\ssmypics.scr"
DEL "%systemroot%\system32\dllcache\ssmyst.scr"
DEL "%systemroot%\system32\dllcache\sspipes.scr"
DEL "%systemroot%\system32\dllcache\ssstars.scr"
DEL "%systemroot%\system32\dllcache\sstext3d.scr"
DEL "%systemroot%\system32\scrnsave.scr"
DEL "%systemroot%\system32\ss3dfo.scr"
DEL "%systemroot%\system32\ssbezier.scr"
DEL "%systemroot%\system32\ssflwbox.scr"
DEL "%systemroot%\system32\ssmarque.scr"
DEL "%systemroot%\system32\ssmypics.scr"
DEL "%systemroot%\system32\ssmyst.scr"
DEL "%systemroot%\system32\sspipes.scr"
DEL "%systemroot%\system32\ssstars.scr"
DEL "%systemroot%\system32\sstext3d.scr"
ECHO.
ECHO. 
ECHO.
ECHO  Updating Windows Components...
ECHO.
ECHO  Please Wait...
ECHO  1 of 5 - Installing Direct X v9.0b...
start /wait %systemdrive%\INSTALL\dx9b\dxsetup.exe /opk
ECHO.
ECHO  2 of 5 - Installing Windows Media Player v9.0...
start /wait %systemdrive%\INSTALL\WMP9\MPSetupXP.exe /Q:A /R:N
ECHO.
ECHO  3 of 5 - Installing MSN Messenger v6.0...
start /wait %systemdrive%\INSTALL\MSN6\MsnMsgs.msi /QB
ECHO.
ECHO  4 of 5 - Windows Script v5.6...
start /wait %systemdrive%\INSTALL\HOTFIXES\TYPE2\js56nen.exe /Q:A /R:N
ECHO.
ECHO  5 of 5 - .NET Framework v1.1
start /wait %systemdrive%\INSTALL\DOTNETFRAMEWORK\netfx.msi /QB
ECHO.
Echo.
ECHO.
ECHO  Installing Critical Updates...
ECHO.
ECHO  Please Wait...
CD "%systemdrive%\INSTALL\HOTFIXES\TYPE1
for %%i in (*.exe) do start /wait %%i -u -f -o -z -q -m
CD "%systemdrive%\INSTALL\HOTFIXES\TYPE2
for %%i in (*.exe) do start /wait %%i /Q:A /R:N
CD "%systemdrive%\INSTALL\HOTFIXES\TYPE3
for %%i in (*.exe) do start /wait %%i /C:"dahotfix /q /n" /Q
ECHO.
ECHO.
ECHO.
ECHO  Removing ASP.NET Account Created By .NET Installation...
ECHO.
ECHO  Please Wait...
start /wait DELUSER /Q aspnet
ECHO.
ECHO.
ECHO.
ECHO  Applying Registry Tweaks...
ECHO.
ECHO  Please Wait...
REGEDIT /S %systemdrive%\INSTALL\REGTWEAKS\tweaks.reg
ECHO.
psshutdown.exe -r -t 60 -f -m "Windows Must Restart To Complete The Installation..."
ECHO.
EXIT

yes that should do it. If you use spaces any more remeber tpo wrap the line like so

"%systemroot%\stuff with spaces\target.txt"

that will also help you out allot.