Hey Staff, I'm not sure but i do believe that when Zibri upgrades his Ziphone versions this makes previous versions null and void! I used the 2.3 version on mine, but when i tried to use it on a friends phone the day thAT THE 2.4 came out it would not let me, so i had to use 2.4! therein lies the problem, there is no GUI version for windows in 2.4, therefore you have to use a command line to use this version. If you are familiar with using the command line it is very simple, 3 commands and you're off and going.