How to root Android Device installed in Oracle VirtualBox on Windows
for root Android-X86 use this :

Download From XDA

Usage: ROOT SCRIPT FOR ANDROID x86 4.3

On android-x86:
Boot up
Press ALT+F1 //or if doesnt work,download Terminal Emulator then open it and follow ...
"cd" to the folder containing this file
Run "sh install.sh" and follow the instructions

On a linux OS boot:
Open your linux terminal
"cd" to the folder containing this file
Run "sh install.sh" and follow the instructions


other links For more details :

How to root device in Oracle VM Virtual Box

How to Root Android Device installed in Oracle VM Virtual Box

How to root Android x86 4.3
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