Interesting stuff from the Aston Log:

Registry Keys to check

  HKLM\System\CurrentControlSet\Control\SafeBoot\Option
  HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
  HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon\LeakTrack
  HKLM\System\CurrentControlSet\Control\Terminal Server
  HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Windows\LoadAppInit_DLLs
  HKLM\System\CurrentControlSet\Control\ServiceGroupOrder\List
  HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced\SeparateProcess
  HKCR\CLSID\{ceff45ee-c862-41de-aee2-a022c81eda92}\(Default)
  !!! HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\system.ini\boot
  !!! HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\IniFileMapping\system.ini\boot\shell
  !!! HKCU\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
  !!! HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon\shell
  !!! HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\DesktopProcess

Stuff to test on Vista 64

  Run Explorer with "Explorer.exe /separate"

Confirmed by Captain: working one time... if explorer.exe started without the param then explorer bar is back

Windows\WindowsShell?.mainfest
What is it used for??

Content with AstonShell?: (need to compare to without Aston)

<?xml version="1.0" encoding="UTF-8" standalone="yes"?> 
  <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"> 
  <assemblyIdentity processorArchitecture="*" version="5.1.0.0" type="win32" name="Microsoft.Windows.Shell.shell32"/>     
  <description>Windows Shell</description>  
  <dependency>
    <dependentAssembly>
      <assemblyIdentity type="win32" name="Microsoft.Windows.Common-Controls" version="6.0.0.0" publicKeyToken="6595b64144ccf1df" language="*" processorArchitecture="*" /></dependentAssembly>
    </dependency>
   </assembly>                               

What's this?!?! maybe try to load as shell service object?!

  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\ShellCompatibility\Objects