I think I could learn a lot from you guys if I understood what you were saying...
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.