Hi there
This is my first posting in this forum and I'm also new to MCE.
My first experience with MCE is a few days old, since three days I have MCE running on my XP Pro box. For the installation I followed Turge's instructions posted earlier in this thread (http://www.thegreenbutton.com/community/shwmessage.aspx?forumid=27&messageid=78447#bm80685). After messing around with .NET 1.1 and after many failed attemps I finally have a working MCE 
My attempt ended up in a slightly modified install script I want to share with the community here. I also want to post a few hints and tricks as well.
1. What has been modified in the new install script?
- installation will now stop when .NET Framework 1.0 installer is aborted
- 'MEDIACTR.CAB', 'PLUS.CAB' and 'SONIC.CAB' and are copied only once to save time during installation
- added echo instructions to make things more clear for the user
2. The new folder structure:
- 'MEDIACTR.CAB', 'PLUS.CAB' and 'SONIC.CAB' are included only once to save space
- renamed folder 'ehshell backup' to 'ehShell patched'
3. Where to get the files from?
Instead of installing the whole MCE system on a PC to copy the neccessary files from, I grabbed them from the installation CDs: just have a look at CD1\I386 and CD2\CMPNENTS\MEDIACTR\I386. For uncompressing the files (ending with '_') use the expand command. Example: 'expand EHOCGEN.DL_ ehOCGen.dll'
I was unable to find a file called wstrenderer.ax_ on the CDs, other posts in this thread mentioned to rename 'wstrendr.ax' to 'wstrenderer.ax' (execute 'expand WSTRENDR.AX_ wstrenderer.ax'). Therefore my folder structure doesn't contain 'wstrendr.ax' anymore.
4. Some issues with .NET Framework 1.0 and 1.1:
There was some confusion with .NET 1.1 on my test system (VMware virtual machine). Because the Framework was already installed in version 1.1, I also installed the .NET SDK 1.1. Unfotunaltely I run into trouble 2 times with 1.1. First the MCE installer reported some errors (at instruction 'rundll32 syssetup,SetupInfObjectInstallAction Freestyle 128 medctroc.inf' in the installation script). The cause was the missing .NET Framework 1.0. After installing Framework 1.0 everything worked fine for me and finally I was able to start MCE. The next problem appeared when I re-tested the installation on a clean XP Pro installation (also using a virtual machine). The installation just worked fine but I was unable to start MCE, the error was caused by the missing .NET Framework 1.1!? The reason was the use of .NET SDK 1.1 for compiling the patched ehshell.exe...
After compiling again with SDK 1.0 I finally had a proper working installation script and all the necessary files :-D
FYI: Microsoft says, different .NET Framework versions can be intalled and used simultaneously on a Windows system. I hope so 
Here we go
Folder structure
¦ install.bat
¦ MEDIACTR.CAB
¦ PLUS.CAB
¦ SONIC.CAB
¦
+---Copy Files
¦ +---Windows
¦ +---Inf
¦ ¦ medctroc.inf
¦ ¦ plusoc.inf
¦ ¦ sonic.inf
¦ ¦ sysoc.inf
¦ ¦
¦ +---System32
¦ ¦ ehocgen.dll
¦ ¦ encdec.dll
¦ ¦ medctroc.dll
¦ ¦ mpg2data.ax
¦ ¦ msvidctl.dll
¦ ¦ plusoc.dll
¦ ¦ quartz.dll
¦ ¦ sbe.dll
¦ ¦ sbeio.dll
¦ ¦ vbicodec.ax
¦ ¦ wstpager.ax
¦ ¦ wstrenderer.ax
¦ ¦
¦ +---CatRoot
¦ +---{F750E6C3-38EE-11D1-85E5-00C04FC295EE}
+---ehShell patched
¦ ehshell.EXE
¦
+---Framewrk
¦ 1.0.3705.0.exe
¦
+---Registry
¦ MCE.reg
¦
+---Tools
sn.exe (from SDK, C:\Program Files\Microsoft.NET\FrameworkSDK\Bin\sn.exe)
Contents of install.bat:
@echo off
rem Install .NET Framework 1.0 if needed
If NOT EXIST "%systemroot%\Microsoft.NET\Framework\v1.0.3705\ngen.exe" call :InstallFramework
echo.
echo Copy Needed Files
xcopy /E /I /Y /H "Copy Files\Windows" %systemroot%
echo.
echo Copy CAB Files
copy MEDIACTR.CAB %systemroot%\System32\CatRoot\{F750E6C3-38EE-11D1-85E5-00C04FC295EE}
copy PLUS.CAB %systemroot%\System32\CatRoot\{F750E6C3-38EE-11D1-85E5-00C04FC295EE}
copy SONIC.CAB %systemroot%\System32\CatRoot\{F750E6C3-38EE-11D1-85E5-00C04FC295EE}
echo.
echo Register DLLs
regsvr32 /s %systemroot%\eHome\custsat.dll
regsvr32 /s %systemroot%\System32\encdec.dll
regsvr32 /s %systemroot%\System32\msvidctl.dll
regsvr32 /s %systemroot%\System32\quartz.dll
regsvr32 /s %systemroot%\System32\sbe.dll
echo.
echo MCE installation will start now
echo When you're asked for the CD, press OK and browse for MEDIACTR.CAB
pause
rundll32 syssetup,SetupInfObjectInstallAction Freestyle 128 medctroc.inf
rem Install Add-Ons
rem rundll32 syssetup,SetupInfObjectInstallAction PlusTheme 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusSpac 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusGold 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusDavn 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusNatr 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusMpix 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusDancer 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusParty 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusAudio 128 plusoc.inf
rem rundll32 syssetup,SetupInfObjectInstallAction PlusCDLM 128 plusoc.inf
echo.
echo Copy Needed Files Again
xcopy /E /I /Y /H "Copy Files\Windows" %systemroot%
echo.
echo Register DLLs Again
regsvr32 /s %systemroot%\eHome\custsat.dll
regsvr32 /s %systemroot%\System32\encdec.dll
regsvr32 /s %systemroot%\System32\msvidctl.dll
regsvr32 /s %systemroot%\System32\quartz.dll
regsvr32 /s %systemroot%\System32\sbe.dll
echo.
echo Backup Original ehShell
ren %systemroot%\ehome\ehshell.exe *.bak
echo.
echo Copy Patched ehShell
copy "ehShell patched\ehshell.exe" %systemroot%\ehome
echo.
echo Prevent strong name errors
Tools\sn -Vr *
echo.
echo Setup Registry
regedit /s Registry\MCE.reg
echo.
echo Installation completed. Start %systemroot%\ehome\ehshell.exe and enjoy!
pause
exit
:InstallFramework
echo Microsoft .NET Framework 1.0 not found!
echo .NET 1.0 will be installed, MCE Setup is not compatible with .NET 1.1 or later
echo Existing newer .NET versions will not be affected
echo.
echo Press CTRL-C to abort
pause
Framewrk\1.0.3705.0.exe /Q
rem check again for .NET 1.0, installation might have been aborted of failed
If NOT EXIST "%systemroot%\Microsoft.NET\Framework\v1.0.3705\ngen.exe" exit
Contents of MCE.reg:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Media Center\Extensibility]
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Media Center\Extensibility\Applications]
@=""
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Media Center\Extensibility\Categories]
@=""
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Media Center\Extensibility\Entry Points]
@=""
ehShell.exe:
Have a look at http://www.thegreenbutton.com/community/shwmessage.aspx?forumid=27&messageid=78447#bm80685. Hint: look for the string "StartupError.NotFreestylePID" in ehshell.il, the line "IL_001e: brtrue.s IL_002d" is found three lines higher.
Make sure you're using .NET SDK version 1.0 for compiling!
Credits, credits, credits: Turge, Cactus, Raphael and tmksnyder!