I've just started fiddling with the registry & didn't fancy the idea of getting shut out of windows by my own stupidity. There is a safer way: use a virtual machine. I've now got an old copy of XP running in a virtualbox machine, with basic4PPC installed in it. Take a snapshot of the system & you can roll it back to a working version, but from outside the OS. VirtualBox also runs under Linux, so there is the possibility of developing software on a Linux box (albeit while actually owning a copy of windows to use basic4PPC & to run the programs).