I tried that but the error was somethign diferent. I incremented the byte pointer for the file data by 2 bytes and then then send it to the uncompress function but it returns the same error but the errors come at diff point. Can you please send me some working code if you have, I'm just trying to open a zip file and select a file then uncompress it. I have read the list of files and created a data structure for each file. Do I need send the byte address of file pointer let me know.