To be more specific about my background, I have just failed to apply (Fall 2015) for Computer Science Masters program from 7 universities (US).
They were Stanford, CMU, UMich, U-Wisconsin Madison, Princeton, UCSD, and Columbia.
I live in a country where English is not my first language (I live in SEA).
I have been working for a telecom company since I was graduated in Computer Engineering.
So now i'm planing to apply for Fall 2016 (Spring 2015 maybe), but this time I would like to focus on Computer Engineering since my work is about
infrastructure, servers, network link, which they are related to Computer Engineering more than Computer Science.
So here are my questions,
If i want to get into top universities (such as the universities which I failed above but I think I will change)
1. How much GRE should I reach ? and to reach that target how should I prepare ?
2. Should I ask the same professors to write me LORs for Fall 2016 ?
3. Do I have to re-test my TOEFL (100 last time which Reading 29, Listening 23, Speaking 23, Writing 25) ?
Thank you for everyone who answers this post in advance.