Hi, Today I tell u how u update your samsung galaxy s3 in your home pc/laptop just simple .no fake . Condition : 1. If your phone is rooted. And you think that back to set your phone official mod.so you dont unroot the phone. 2. You check your phone in settings»about»status»Device status : custom .so you will see that your phone in custom mod its means your phone is rooted not official mod. 3. Go to this link https://sammobile.com and in search function find your mobile firmware file and download it but first of u check your firmware basemodel number go to settings»about»basemodel number. and download firmware correctly indian format ( IND) . 4. GO TO PC/LAPTOP AND DOWNLOAD ODIN SOFTWARE YOU SIMPLY SEARCH THE SOFTWARE BY HELP GOOGLE ENGINE. . 5. when firmware download paste firmware to you pc/laptop dekstop and open odin and switch off your phone and press volume down »phone centre button and powekey sametime and you will see phone is on downloadmod and connect tje phone .port added in odin software. . 6. And select pda/pd browse your file firmware you download and flash it the phone it takes 10-15 minutes. .wait. and enjoy .and then when phone on then in phone inbuilt format option format memory card and phone also . enjoyy