i was given a samsung captivate from att. with 2.1update-1 firmware and doesn't have unknown sources. now what i did i downloaded the KIES MINI. my phone was updated to gingerbread and everything just follows. no sweat for me. well, hope this helps.
Ok so im still a newbe on the android phone.. Have a quick question? So i just loaded some apk files to my sd card. but when i try to install them with astro or appinstaller, i get install blocked .. for security , your phone is set to block installation of appplications not sourced in android market? how do i take that block off. yes my phone is rooted. att captivate. os 2.1..