Just bought a Galaxy S3 from someone and he always had it rooted, so he factory reset the phone for me before he sold it at least but setting up, im having problems updating the firmware (standard method). at first it couldnt even register Device. So i clicked 'unroot device' in SuperSU then it worked to download package. After package downloaded, i had to restart it said. it took me to console page instead of just normally restarting then after boot it just popped up saying something like 'cannot upgrade firmware, try again later or try using Kies' Kies wont detect my phone. but my PC does no problem. Any suggestions how to upgrade the phone to 4.3? or at least 4.2??? Im extremely new to all this root stuff and hardly understand it. so please simplify suggestions and give me step instructions!