Separate Explorer Process
Separate explorer file manager from explorer shell. This makes it possible to use the explorer file manager without the shell (taskbar, desktop) starting up.
Key: HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer
Value: DesktopProcess (0/1)

Set New Shell
Sets which exe to start as shell on login.
Key: HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\winlogon
Value: !Shell (String: Path to exe)

Ini File Mapping Fix
Change to per user shell settings
Key: HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\IniFileMapping\system.ini\boot'
Value: String=USR:Software\Microsoft\Windows NT\CurrentVersion\Winlogon
Original Value: SYS:Microsoft\Windows NT\CurrentVersion\Winlogon

Read More: http://msdn.microsoft.com/en-us/library/ms838576(WinEmbedded.5).aspx