I had the same issues a while back with kies total nightmare there was a number of forums on it it has to do with a driver error some poo if u have WiFi u can update via WiFi otherwise if u don't McDonald's always has free WiFi so maybe a mcmuffin and a coffee whilst u update
Ok I might be a total Div but wat the heck does any if that mean. My s3 is running like a total bag I'm getting real over it left apple cause my 4s was total crap love my galaxy but it's had issues fir a bit but its so bad now. I'm in Australia so don't think 4.1.2 has hit us yet. Hubbies...