The good news is, the ActivePerl installer does modify your AUTOEXEC.BAT. At least, it tries to - I don't know why it would have failed to do so for indapa. It should also ask you to reboot, as that is the only way that the environment can be set for all subsequent DOS windows. The bad new is, cannot be done through the registry, but requires a reboot, and DOS (and AUTOEXEC.BAT) load first, before the Windows 9x GUI, and are thereafter in memory. The only thing the registry gets is file association information (so Win9x knows what to do with a *.pl file, etc.) and some registration/uninstall information. All of this applies to Win9x of course, and not to Win[NT|2000|ME|WhateverTheyAreCallingItThisMonth].