Requirements:
the below mentioned things are necessary to run android os in the desktop or laptop.
Android x86 ISO( download the suitable versions)
-A usb pen flash drive
Hard disk space of minimum 3gb for froyo;9gb fr jelly bean (4.2,4.3);11gb for kikat(4.4.2);13gb for lollipop(5.0)[the lollipop is still known to have much bugs its better to get kitkat for less bug issues] virtual box ( software) for creating a bootable pen drive.
Step by Step Tutorial :
Download the android latest iso files from the below link provided: https://code.google.com/p/android-x86/downloads/list Try at your own risk before running android on desktop or laptop just reboot the system once As its a multi-boot setup yo can choose either the windows or the android that you have just installed on your laptop or pc. If your cant understand the process of installing the Android you can just use some third party apps for running android apps in desktop or laptop . the best third party app for installing android apps on desktop or laptop is Blue stacks. its a free ware app developed by some dev developers so that some people who cant afford android devices can use the android apps on desktop or laptop.