I have installed P5 to my "D" drive but it has written files onto my main "C" drive. After a monumental crash trying to get it in, I did a format and re-installation. The challenge code was still there afterwards. I read somewhere in the forum that the protection system is based on the serial number of your main drive and that only a low-level format (filling the drive with zero's) would remove it. A disk image would only work on the drive that you originally installed on and got a response code for... there would be no point in having a protection system if this was not so. A possible solution to keeping Poser seperate from the rest of your programs would be to have two hard drives with Win2000 installed on both of them. You could keep one for P5 and get a code for it, etc and boot up into the system to use it. For your sanity's sake, get the CL updates and apply them before using P5 - I have had no problems since doing so. If you have two drives available, there is no reason why you could not back up your complete Runtime folders to it at regular intervals for both P5 and P4. I currently do this and have separate Runtimes for posette, victoria and experimental stuff. However stuffed and unworkable the original gets, you only have to delete it and replace it with a tidy back-up copy. This helps prevent your finger wearing out scrolling down the MAT/Pose files.