What is this "Virtual Box OSE"?

I understand the concept. Virtual PC on top of a real pc. Yes... But how does it work? Do I need an image of an OS?

I think I ask because I come across an error upon booting Virtual Box: Fatal: No bootable medium found. System halted.

I set up the OS for Windows XP. Kept everything default. I think that was how I was instructed by my friend. (He's the linux guru in my office. but he's gone for the week)

Thanks.

VirtualBox and VMWare both create virtual hardware on which you can install an operating system of your choice. Yes, you will need an installation disk. You can pretty much treat it like another machine.

You still need to install windows. You have a few options. You can insert the install disk and forward it by clicking on CD/DVD while the virtual computer is off. Alternately, if you happen to have an .iso of the bootable disk, you can forward that as well, through the same menu. Good luck.