http://uk.samsungmobile.com/pmgmvst....70107&coflag=0 (it is modem driver it needs to be downloaded for xp )
http://uk.samsungmobile.com/pmgmvst....70108&coflag=0 ( it is for vista ) install modem drivers firstly then you can install rom exe files.
2.) download an hex editor i preffered HxD as editor like melgurth and choose one of these exe files given above and at the end of last line at editor you will see the version of rom ( it is seen as i780CS) change it with your version ( mine was i780pdxhi1 so u will change that line i780DX) then save as you exe file somewhere on your pc. by the way
3.) Start exe file which is edited by yourself.the progress is shown at pc when rom download is finished then unplug your usb cable and power on your i780 wait for a while and there will come Language settings choose which language you want then system will be in that language
4.) as final, there is no operator settings in system tab it means you have to add mms and internet settings by manually.if there is a cab file for it can you share with us?