for %%i in (C D E F G H I J K L M N O P Q R S T U V W X Y Z) do if exist %%i:\WIN51 set CDROM=%%i:
set wpipath=%CDROM%\wpi

SET KEY=HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnceEx

REG ADD %KEY%\999 /V 1 /D "%wpipath%\WPI.hta" /f