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How to Run Windows and OS X on the Same Mac

A hybrid engine that runs on gas and electricity. A football star who plays both defense and offense. A politician who understands social justice and capitalistic expansion. These anomalies are rare, but in the world of tech, they are almost unknown entities. For anyone who owns a Mac, it might seem a bit odd to think you can run both the Mac OSX and Windows, and switch effortless between them. Yet, not only is it possible to live in these two universes, it actually makes perfect sense.

One reason is that there are a handful of applications, and even a few Web sites, that only work on a PC. The most obvious examples are enterprise-level tools at work, including some apps from Oracle and Microsoft that do not run on the Mac platform and probably never will. A few Web sites require an older version of Internet Explorer, which is not even offered for the Mac anymore. And, many of the latest games — such as Mass Effect 2 — are not available for the Mac.

Fortunately, Apple offers an application called Boot Camp which allows you to run Microsoft Windows as though it was meant for your Mac all along. A few other virtual machine tools exist as well, including Parallels 5 and VMware Fusion, adding a few features and adding some performance perks. For more industrious users, you can also use a program called Crossover which actually runs the Windows app as though it works on a Mac, even though this approach is a bit hot or miss.

For those who want to run both Mac and Windows, here’s an overview of the advantages to each approach, and a few pitfalls to avoid along the way.

Apple Boot Camp

The free Boot Camp app for Mac, included with every Mac, has one major difference compared to Parallels and Fusion: it requires that you reboot your computer. That’s only a minor annoyance, but Boot Camp does require you to live either in Windows or Mac and switch back and forth.

Boot Camp also supports Windows 7, but you do need the latest Mac OS X v10.6 Snow Leopard version and the Boot Camp 3.1 Update, which you can download using the system update utility or get directly from the Snow Leopard install disc.

The important point to make here is that you will need your own licensed copy of Windows 7 (or a previous version) and, using the Boot Camp Setup Assistant (located in Applications/Utilities), you will need to install the operating system as though you just bought a brand new PC. After the install, you will also need to install the Mac drivers for Windows. (That might seem odd, but this is the step that makes Windows work with the Mac hardware.) Just insert your OS X DVD when prompted. You will also need to run the Apple Software Update utility from within Windows to update the drivers.

Then, to use Boot Camp, you just hold down the Option key when your Mac boots. You will see an option to boot into Windows or the Mac. Select the one you want and you’re off.

Now, about performance. It’s obvious that a Mac is designed for the best performance with OS X. Running Windows, you will notice the speed is mostly adequate, but not that comparable with a brand new laptop from, say, HP or Dell that is designed (and thoroughly tested) for Windows.

VMware Fusion 3.1

While Boot Camp is a free utility, Fusion 3 costs $80 and is an extra app you need to purchase and install. However, it offers several distinct advantages. One is that the app runs in a window, so you do not need to reboot your Mac to use it. This means, when you do need to run the Windows version of Microsoft Office, or that one pesky Web site that uses ActiveX controls and requires the Windows version of Internet Explorer, you can just run Fusion and start using the apps you need.

The obvious downside here is that your Mac will take a performance hit. In most cases, though, you will find that the virtual machine actually runs smooth enough for most apps. Fusion actually uses a powerful graphics driver to support the latest Windows 7 features, such as the Aero interface that has the see-through windows look and allows you to flip through windows as large panels.

Loading Fusion 3 works a bit like Boot Camp. Once you run the app, you do need to install Windows 7 — it is not included with the app. However, since you do not have to reboot, the process is actually smoother and does not require the extra driver updates that you need to do with Boot Camp.

Now, you might wonder: what about games? For most Mac users with a recent laptop or desktop, game performance is actually fairly good. Fusion 3 supports OpenGL 2.1 and DirectX 9.0c Shader Model 3, so recent games such as Aliens vs. Predator will run almost as smooth as they do on a PC.

That qualifier “almost” is important. There are times when Fusion slows to a crawl, presumably because of how it runs in a window. You also can’t run any other apps in the background, and virtual machine instances are highly dependent on your RAM load — in fact, if you plan to use Fusion (or Parallels, for that matter) routinely, you might consider adding an additional 2GB of RAM to your Mac.

Parallels Desktop 5

Parallels also runs in a window, supports Windows 7, and costs $80. So what is the main difference between this tool and Fusion 3? One is that Parallels does run a hair faster than Fusion, although VMware did address speed issues with the Fusion 3.1 release. Parallels loads in the same way as Fusion — it requires that you use the Windows 7 installer disc and does not have the same driver install steps as Boot Camp. Once loaded, Parallels can run in a full-screen mode as though you booted from Windows.

Parallels also adds a few extra features. One is that you can actually add Windows apps to the dock and start them as though you have the Windows app loaded on your PC. Granted, this still loads the virtual machine and then starts the app, but it makes the process a little faster. Parallels adds a unique “Mac theme” option so you can change the Windows desktop to look more like a Mac.

Parallels has a slew of minor enhancements as well — some you may never use. For example, you can configure the virtual machine to load every time you start your Mac, a tool for transferring files between the Windows virtual machine and the Mac, and speech recognition features. I’m not sure Mac users really want to use these extra options, since most will likely just do what they need to do in Windows and go back to Mac, but they do add to the overall value.

Codeweavers Crossover

One last option if you really need to run Windows apps on your Mac is CrossOver Mac, a program that uses the Wine toolkit. CrossOver makes it look like a Windows app runs natively on your Mac, mostly by loading just the required application framework. So, for example, if you want to use Microsoft Office 2007, you can load CrossOver and then install the app and run it in a window, without actually loading Windows at all.

When CrossOver works, it works wonders. The app supports popular mainstream apps like Microsoft Office and Outlook, but not any of the major Adobe products. A separate app called CrossOver Games lets you play a small number of older games, like the first Call of Duty games, but not recent titles.

CrossOver is a good idea, though, if you just need to run basic apps and don’t want to bother installing Windows itself. And, the costs just $40 so it is half the price of a virtual machine app.


These dual-boot, multi-platform tools do solve a common problem on the Mac: at work or at home, there are times when you really need to run a Windows app. The Mac might be your preferred platform, but with a few extra software tools, you can also live in a Windows world — if temporarily.

Like VMware Fusion 3.1 and Parallels Desktop 5, VirtualBox is a virtual machine that allows you to run a full version of Windows within a window on your OS X desktop. Unlike either flashy commercial variant, it’s also free and open source.

Since it’s not focused solely on emulating a PC from a Mac, the consensus seems to be that it’s not quite as refined, but it will do the same job if you’re patient. For instance, after installing Windows, you’ll want to add “guest additions” that will make the cursor stutter less and a special feature to intelligently resize the native Windows resolution as you stretch and expand the window it’s in.

VirtualBox can also run other operating systems like Linux, OpenSolaris, OpenBSD, and DOS (useful for those classic PC games you wish you could run!). You can even run a separate installation of OS X from within OS X to, for instance, test out buggy software without messing up the clean installation you use every day.

Although you’ll have no one to call if you run into installation problems with VirtualBox, like most open source software, VirtualBox provides fairly active forums with plenty of helpful users.