After installation of Android Studio and installation of packages you required using Android SDK managers. You should install Intel Hardware Accelerated Execution Manager.
Intel Hardware Accelerated Execution Manager is used to avoid error during Android virtual device creation.
If you have done the standard installation this is should be already installed, if not you can install it.
Follow below steps to install it:
Step 1: Launch Android App.
Step 2: Go to Configure -> Android SDK. [Alternative way is go to Tools->SDK Manager]
Step 3: Click on SDK Tools tab and verify "Intel x86 Emulator Excelerator" installed, if not, you can install it by selecting the checkbox and clicking on OK button.
Step 4: You can increase RAM during installation.