Download my Mod Assistant http://www.thegtaplace.com/forums/index.php?showtopic=21027 . When you run it, click the 'Open' button and load the files.txt (make sure you have the correct version selected at the top first). After the files are loaded, scroll down and find the handling.dat file. Select it in the list, then click the button labeled 'Backup'. It will bring up a menu, on the menu click 'Selected File'. Then you are free to edit the file and the game will still launch. Alternately, if you don't feel like scrolling the list to find the specific file. You can just click the 'Backup' button to bring up the menu, then click 'All Files'. This will backup all the files listed in files.txt and allow you to modify any one of them without worry of whether the game will launch or not. Let me know if it works or not.
Well , now i can change the handling.dat and i renamed too,but the game not launch .(if i change one single number ,the GTA 4 will not work).But i can have a new handling.dat ,so what tool i must have to launch the GTA 4?
Thank for all your help , i have sure we will make the NEW HANDLING.DAT work.
