Modules not being detected




I’ve been facing this problem since the day I decided to install native script on my laptop. I downloaded nodejs and all the other programs needed for the environment like Android Studio, JDK… Now when I type “tns doctor” in the command prompt, I get the following:

I tried npm install -g tns-core-modules, npm install -g tns-android and npm install -g tns-ios.
It shows that the install was successful but tns doctor still shows the same result afterwards!
Please help!