You guys are mistaken here. this ROOT GUIDE is for A205 series and it doesn't work with the A207 Series. When you say A20 there are 3 type of A20 series which are:
A20e (A202F) ,
A20 (A205F, A205FN, A205G, A205GN, A205S, A205U, A205W, A205YN, A205DL, A205F, A205M) ,
A20s (A207F, A205M)
Please mention this topic is for the A20 series only which I gave above. I tried this method for A20s - A207F for more than 5 times and it didn't work at all.