Download latest version of Android Studio from website https://developer.android.com/studio/index.html and install it from executable file.
Now you will get a welcome window of Android Studio Setup. To start installation click on Next button.
Now select all the components then click on Next button.
Now agree the license agreement and select the Android Studio installation location then click on Next button.
Now click on install --> next --> finish button.
After finish the setup, now select the radio button "I do not have previous version of Android Studio...." then click Ok button.
Now click on Next button on Android Studio Setup Wizard.
Now select standard type and click on Next button.
Now on Verify Setting window click on Finish button.
Now on downloading component window click on Finish button and complete the installation.
Congratulation !!! You can start your new application now.