One last note about installation: Make sure you turn off the screensaver in your guests. This cooperation includes things as important as proper cut-and-paste behavior and file sharing. One of the unavoidable facts of virtualization - no matter which system you use - is that virtual machines need 'guest OS tools' installed to cooperate with the host OS.

Having recently installed Windows XP on bare metal, I can tell you that using a virtual machine makes installation easier. They ask for a few parameters, including the product key, and then take over from there. Creating a new Windows virtual machine is dead simple in either package. Most people have never installed Windows. Making Windows easy is mostly about installing the OS. Switchers who love the Mac experience but have 'that one Windows' application they can't live without are the sweet spot. Can you run Linux, Solaris, or even FreeBSD? Sure, but you're not in the target demographic. Making Windows easy The stated goal of Parallels as well as Fusion is to make life easy for people who want to run Windows on their Mac. For the cost of Parallels or Fusion (both $79) you can run your Windows copy on your Mac. Similarly, if you're switching from Windows to a Mac, buying a copy of QuickBooks for OS X will cost you $200 even though you already own a perfectly good copy for Windows. For example, the organization I work for has an enterprise license for Office on Windows, but not on OS X, so I can load Windows and Office using the enterprise license and get an Intel-native version of Word that runs on my Mac for a fraction of the cost of Word for OS X. Of course, if you already own the Windows software you want to run, then it's even easier to become a Mac bigot.

Keep in mind that some Windows editions are not licensed to run in a virtual machine - notably Vista Home Edition - so you may need to buy a more expensive edition than you otherwise would. Naturally, to run Windows in either Parallels or Fusion, you'll need to buy not only the virtualization software but Windows itself. Thus, Parallels and Fusion can help take the sting out of the premium price of a Mac. The value proposition Virtualization won't necessarily save you on software costs, but the ultimate benefit is being able to run OS X and Windows (not to mention other operating systems) without having to buy two computers.

Apple parallels vs vmware vs fusion