Prerequsites: Installed Windows 7 WAIK
Link : [1] http://www.microsoft.com/downloads/details.aspx?FamilyID=696dd665-9f76-4177-a811-39c26d3b3b34&DisplayLang=de

1. Copy PE Files
  “%programfiles%\Windows AIK\Tools\PETools\copype.cmd” x86 c:\winpe_x86
 
2. Copy WIM File
  copy “%programfiles%\Windows AIK\Tools\PETools\x86\winpe.wim” c:\winpe_x86\ISO\sources\boot.wim
 
3. Mount WIM File
  Dism.exe /Mount-Wim /WimFile:c:\winpe_x86\ISO\sources\boot.wim /index:1 /MountDir:c:\winpe_x86\mount”
 
4. Copy ImageX
  copy “%programfiles%\Windows AIK\Tools\x86\imagex.exe” C:\winpe_x86\mount\Windows\System32
 
5. Copy AddOn’s if wanted
  xcopy “C:\AddOns” C:\winpe_x86\mount\Windows\System32 /S /H
 
6. Add Drivers
  Dism /image:c:\winpe_x86\mount /Add-Driver /driver:“C:\Drivers” /recurse /LogLevel:4
 
7. Add Packages if needed
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-hta.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-legacysetup.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-mdac.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-pppoe.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-scripting.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-setup.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-setup-client.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-setup-server.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-wds-tools.cab”
  Dism /image:C:\winpe_x86\mount /Add-Package /PackagePath:”C:\Program Files\Windows AIK\Tools\PETools\x86\WinPE_FPs\winpe-wmi.cab”
  Dism /image:C:\winpe_x86\mount /Enable-profiling

8. Add Hotfixes
  dism /image:C:\winpe_x86\mount /add-package /packagepath:“C:\Hotfixes”
 
9. Unmount PE
  dism /Unmount-Wim /MountDir:C:\winpe_x86\mount\ /Commit
 
10. Create Boot ISO
  “%programfiles%\Windows AIK\Tools\x86\oscdimg” -n -bC:\winpe_x86\etfsboot.com C:\winpe_x86\ISO C:\winpe_x86\winpe_x86.iso
 
11. Creat Boot USB Stick - USB Stick must be formated as NTFS and the partition on the USB Disk must be active
  xcopy “C:\winpe_x86\iso\*.*” /e g:\