Gradle is taking too much time to build

Hi, i’m new to android studio but when ever i make a change and run then gradle is taking too much time to build for start it almost takes 20min and then after each change (even only text change) it takes 4-5 minutes for each time when i click on run button.
My system info:
Intel Core i3 2330M, 2.20GHZ
Ram: 4GB
OS: Windows 7 64bit
Android version: Latest

i know these specs are slow but i have seen many people using same android studio version on core 2 duo 4GB RAM and core i3 4GB RAM. and their gradle is taking 2-3 minutes for the first time build and then less than 30 seconds for each build can you please tell me what is wrong with my android studio? or what kind of settings i can do to make it better?

You could try gradle build --profile to see where the time is being spent.

More info here