Almost an answer to using large .iso files

I my last post I complained and weeped about having a large .iso file and no DVD burner. Today I almost found an answer. It is called a virtual machine. A What? Let's say you are running Linux on your machine everyday and you want to use a program that's only found in MS Windows. You could install and setup an emulator which forms a so-called compatibility layer, allowing you to run some MS Windows applications.. "OR", you could run MS Windows inside of a file setup as a virtual machine that resides in the Linux file system. That means that MS Windows would run as if it were a Linux application. I believe you also would have Windows settings, internet connectivity, etc. Are there any advantages to this madness? Yes, the most obvious one is that you don't have to dual boot into one or the other operating systems. You could use both at the same time!! There are possibilities here. The second is that you don't need to burn a CD or DVD at all.
So, how does this virtual wonder work? It is hard to explain but, computers are all about managing memory and keeping one operation from crossing over into another. A virtual machine allocates some disk space and some memory space separating it from the main operating system's usage so that a second operating system could function in that space. Then through the magic of the GUI, you can interact with it as if it were the main operating system. It will turn a .iso file into a virtual disk so you can boot from it as if you were starting a program.
One virtual system is called VMware which has been around for ages. I think it is a little complicated for me but it has a lot of bells and whistles. Then there is VirtualBox. VirtualBox comes in MS Windows flavor and Linux flavors. I loaded it on both my XP and my Kubuntu installs.
It was quick and fairly painless. So, now I don't have to burn or boot from a CD.
Are there any problems, I mean since I did mention I almost had an answer? Well, yes. If you live in a 32-bit world as most do then there is no problem. If you , are running a 32-bit or a 64-bit main (or host) operating system then you can not install a 64-bit OS as a (guest) virtual machine. There is no support (yet) for 64-bit OS to run as a guest. To be a little more precise, it depends on what CPU you are using. You have to read the fine print in the docs.

So, to answer my main question, is it possible to take a .iso file copied to a hard drive and boot it as if it were a CD/DVD? Yes and No. Sure I can run a Fedora 7 32-bit .iso but I want the 64-bit one that was made for my system. I will just have to byte the bullet and buy a DVD burner.