Alanoll, ok, thx about the info, just i have something to add. I'm using this and it works (environment variable used) HKCU,"SOFTWARE\Microsoft\Windows\CurrentVersion\RunOnce","label",0x00020000,"%%systemroot%%\inf\file.ext" Maybe that's because it's in hivedef and applied on first logon. edit: I overlooked "CUSTOM value", not environment...apologies (it's those %% that triggered me). Lets leave the post for him to see how to use environment variable