OK, to simplify.
There is a computer running Windows XP. HKMk23 is looking at installing the Linux operating system to his computer.
A friend with a Macintosh showed him the computer running Mac OS X (the current operating system on a Mac) with a copy of Windows XP running in a virtual machine.
The virtual machine simulates another computer and enables one to run a different operating system within their current setup. For example, with PearPC, I'm able to load and use the Mac's operating system while running Windows.
I recommended that HKMk23 look at partitioning (splitting) his hard drive and installing Linux on a freed portion of that hard drive.
I understood what was desired with the computers. What I have difficulty with is the the technical jargon that is used to get the desired outcome. It has nothing to do with your explanation, Jon. It's my brain. Some days, I can't even figure out how to turn the TV on. I'm series.
The big deal, here, is that I'd STILL be able to boot up my computer using my backup hard drive in the event that my primary hard drive died.
Just using XP, I can't do that; XP will not let me, which is why I was offline for ten days when my old 120GB hard drive failed. Yeah, I had my entire system exactly duplicated on my 160GB backup drive -- that's called an "image" -- and you'd think that I could have just swapped out the hard drives, set the BIOS settings to the new drive size and booted right up just like always.
XP doesn't work that way, though, and if you try that you end up with a perfectly good hard drive filled wit hdata and applications safely tucked away inside of a totally broken installation of XP that petulantly refuses to work.
Setting up the dual-boot would still leave me able to boot up in Linux and repair my crapped out XP partition from there.
Copyleftist sabotage!!!