How To Instal Windows XP/Vista on Virtual Box

Welcome to the New Virtual Machine Wizard!
1.  First of all, run the Virtual Box machine was you instal, then push New button and click NEXT.

VM Name and OS Type
2.a  Give name whatever you like, i input name Suikoden for example.
2.b  At tab Operating System, choose one of the list OS which will you instal on Virtual Box.
(here i use Microsoft Windows with Windows XP version for example)

Memory
3.  At tab Memory, you have to set how much memory or RAM will you use for Virtual Box. Here i set 512 MB RAM to use for Virtual Box, after you set Memory, then click NEXT.

Virtual Hard Disk
4.a  Checklist Boot Hard Disk (Primary Master) and,
4.b  Choose Creat new hard disk, after that click NEXT button until you get to tab Hard Disk Storage Type.

Hard Disk Storage Type
5.  At tab Hard Disk Storage Type, choose Dinamically expanding storage, then click NEXT button

Virtual Disk Location and Size
Now you get on Virtual Disk Location and Size tab 
6.a  Let the name on Location same as default (no need to change it)
6.b  Set how much hard disk you will spend for making hard drive on Virtual Box, then click NEXT

PS: if you want to instal Windows XP OS, you just need spend 2 GB from your hard disk, but if you want to instal Windows Vista OS, then you will need more GB hard disk to spend up.

Now you already done making hard drive on Virtual Box for instaling your OS there. Insert your CD or DVD Windows XP OS, or you can mount OS Windows XP.ISO using nero, Alcohol 120%, or daimontools

7.a  After you insert your CD or DVD Windows XP OS, push or click Settings after then choose System menu 
7.b  Checklist CD/DVD-ROM and Hard Disk on Boot Order: tab

8.a  After you set the Boot Order: , now choose CD/DVD-ROM menu then checklist Mount CD/DVD Drive
8.b  Choose CD or DVD RAM drive where you insert CD/DVD your Windows XP OS. I insert my cd at DVD-RAM drive (F:) 
8.c  Click OK, then click Start button to start the installation.

Wait till you finish install your OS Windows, then you will have Windows XP on your Virtual Box