You probably know that Windows 8 comes in two different versions—Basic x86 Windows (this is what you use now) and Windows RT. They have similar names. They look the same. But there are serious differences between the two—ones you should know about before you plunk down your cold hard cash on a Microsoft tablet.


Surface—and other Windows tablets that follow it—will come in both Windows RT and full Windows varietals. Which is great! More choice is always better. The problem you're going to run into, though, is that the gap between RT and x86 is as wide as that between iOS and OS X—except the two Windows offerings look exactly the same at first blush.


There are a ton of benefits to using RT, like better battery life, lighter weight devices, cheaper price points. But there are limitations, too. Here are a few of the big ones.

Won't Run a Lot of Your Programs

The most basic way that Windows RT hamstrings you is also the most comprehensive: You cannot run many of the same programs that you do on your regular desktop PC. And the apps you can use have to be updated to run in Metro/Modern/whatever on RT.

For a lot of basic tasks, that's not an issue. Especially not for students, since RT comes with a free, full version of Office 2013. But the absence of legacy software will be a problem for anyone else who's bought into the Windows ecosystem over the decades and expects their programs to work across their devices. They won't. The full x86 Windows tablets—like the Surface launching three months from now—can run basically any Windows program you've bought in the last several years.

Bottom line: If you're someone who needs specific programs for work—even something basic like Photoshop—you're going to have to hold off on an RT machine.


Limited App Selection

This one should be just a temporary snag, but the app selection for Windows RT isn't as robust as you're used to. In addition to not running legacy x86 apps, the OS can also only install apps through the Windows Store. So, all of those certification issues that you've heard from the gaming side of things? While they won't matter all that much on regular Windows 8 (which can grab programs from anywhere), they could severely limit the apps that you'll see on the RT platform for a while.


Right now, there are 5,562 total apps in the Windows Store worldwide—3,488 in the US—and 94 percent of them are Windows RT. compatible. That's a decent number, and includes support from heavy hitters like Netflix, Evernote, and Amazon. The top-notch first party services from Microsoft help too. But Android 3.0 Honeycomb got rightly skewered for having such a lackluster offering of available tablet apps, and RT's numbers are in the same ballpark. Among the missing notables: Twitter, Facebook, and Spotify. Again, x86 Windows tablets won't have this problem; they can run anything that works on your desktop today.


Thankfully, RT does come with that full Office 13 suite. Office RT will include Word, Excel, PowerPoint, and OneNote, and syncs your documents over SkyDrive.


Less Open

A lot's been made about the Windows Store predominance moving Microsoft away from Windows being an open platform. Full Windows 8 is going to remain more or less the same—you can still download an app from anywhere and install it, without going through any official Microsoft channels. But buying and installing stuff on RT devices is pretty much like doing so on an iOS device: It only works through Microsoft's Windows Store. There's nothing inherently wrong with that, but it's different. And it's going to rub a few people the wrong way.


There's a chance you'll be able to sideload apps through Windows RT architecture—you can on Windows Phone 8—but it will likely be more trouble than it's worth.

Windows Media Player/Center

If you use Windows Media Center as your home DVR, you're also going to need an x86 machine to control it, since RT doesn't work with WMC. It also doesn't come with Windows Media Player, but that's not a big deal since the onboard media players will handle most of that load.


Business

Business users—of which Microsoft has more than a few—should be particularly wary of RT. Most importantly: You cannot use Windows RT with a Windows Active Directory domain. So if you need AD to be active for work, you've got to go x86.


You also won't get Outlook with your RT Office 2013, so you'll have to use Mail and Calendar to sync up with Exchange. That's not a huge compromise, but with how rigid some offices are about keeping everything standard, it could be a deal breaker. And the apps you do get with Office 2013 will have to be activated for use in a business setting.

Should You Wait?

For most casual consumers, the folks who want to use their Windows tablet like they would an iPad, Surface should be plenty fine—especially once Microsoft gets that app store populated. But Microsoft hasn't done a particularly good job explaining the difference between RT and x86, even to its own employees. And the differences that might not matter to one person might be a deal-breaker for others.