Virtualbox OSE + WinXP

So is the host Ubuntu based?
If you have used wubi to install ubuntu you will not be able to "boot XP" using virtualbox, it just doesn't work like that.
How do you "download XP on the partition"? It makes no sense..

Thank you Actionparsnip,

I used http://www.ubuntu.com/desktop to DL Ubuntu, I DLed onto a cd via ISO file. Not sure what wubi is...

When I make "new" on the top left, it starts a wizard, and about half way through, it asked "Select a hard disk image to be used as the boot hard disk of the virtual machine." then gives me 2 options, create new hard disk, and use existing hard disk. I tried both, but it asks how much space do I want to save for this OS. But that "saved" portion does not have the XP OS that I already have on my computer.

I do not know which OS is the host. When I boot my system it asks which OS I want to use, the selected option is XP, but Ubuntu is below it.

Ok so you are using virtualbox to virtualise Ubuntu?
I'm guessing from your text you also have a virtualised XP system...is this right?

What do you mean by Virtualise?

If you use a software to run a system inside another like VMware or virtualbox then the guest system is virtualised. If you have 2 virtual systems then you cannot access both as you wish but you can run both and use a LOT of RAM but they will be able to communicate like 2 PCs on a network.

If you have an XP virtual system and a virtual drive, you can choose this to install to, you will need to resize the NTFS partition on the "drive" to make room for Ubuntu.

I do not THINK Ubuntu is virtualised, I load it from the bios, I do not log into Windows to run Ubuntu, but I do want to Virtualise XP. I know World of Warcraft uses about 1500mb of RAM on my laptop. So I let Windows XP use 1500mb out of my 2g of RAM. I do not have a ton of RAM to use on running both of them as virtual. Ubuntu thinks I have a 15g HD, because when I Installed via cd I told it to use 15g (thinking the OS would take up that much). I have not been able to find any of my Windows XP files, WoW takes up like 30g, I should be able to find that somewhere... I do not have another hard drive to use as JBOD for another OS.

So the situation is that you have XP and Ubuntu separately installed in a dual-boot configuration, and, while running Ubuntu, you want to be able to use the XP system through VirtualBox?

You'd need to set up raw disk access for this, which is not simple to explain, and can cause more problems than it solves. Visit virtualbox.org for the documentation and forums that might be more useful to you on this occasion.

If, however, all you want is simple access to files (i.e. not run programs) saved on the XP partition, you can choose to mount that partition within Ubuntu, so you can open and save the pictures, documents, etc. that you have there.

What I understood:

1st partition XP
2nd partition Ubuntu
   VirtualBox OSE
   Virtual Machine 1500MB RAM & 15GB of hard disk
        XP currently, and WoW in the future
Problem: WoW needs 30GB of hard disk

Not all Windows software works well under VirtualBox, when they use DirectX. Do you have check on Google if they are already people running WoW under VirtualBox.
If you have enough hard disk space on your Ubuntu partition, you can make a second virtual hard disk of 30GB or extend current virtual hard disk of 30GB (could be done via Gparted).
If you have not, but have enough space on Windows partition, you can:
   mount Windows partition under Ubuntu
   create a shared folder with VirtualBox in this Windows partition

Can you explain which solution fits at best your need.