While Microsoft is spending a small fortune promoting its next-generation Windows 8 operating system, it also has another new operating system called Windows RT, which actually powers the company's Surface tablet and a few other devices.
Superficially, the operating systems look and feel the same. But Windows RT is designed for devices running on ARM chips, which are used to power smartphones and tablets and are considered more power-efficient.
Windows RT is more like "Windows Lite" than a full-blown update to the operating system. It's Microsoft's attempt to make a controlled environment similar to Apple's iOS, and that means Windows RT has some big limitations compared with Windows 8.
If you're thinking of buying a Windows RT device, there are a few things you should consider. Here's CNET's rundown of Windows RT's top 10 drawbacks:
1. Flash only works on approved sites. Think you'll be able to watch all those Flash-based videos using your new RT computer? Well, think again. Flash will only run on sites approved by Microsoft. Lucky for you, CNET is one of them.
2. So-called legacy apps -- the traditional programs for older versions of Windows -- won't run on Windows RT. That includes some pretty popular offerings like iTunes and Adobe Photoshop, and . And forget about playing some of the top games. World of Warcraft and Call of Duty, among others, aren't currently offered.
Of course, this could all change tomorrow, but for now, these apps aren't available.
3. Apps can only be purchased through the Windows Store. If you think you can buy software at Wal-Mart or another retailer, think again. Windows 8 software won't work on Windows RT devices, and neither will software purchased from places other than the Windows Store. That's similar to how Apple limits iPhone and iPad purchases to its iTunes Store. Android, however, can be enabled to install apps not purchased in Google's Play store.
Another confusing factor is that Microsoft will offer games in the Windows Store, as well as the Xbox Games app.
4. The apps that are available are pretty limited. Microsoft has said it expects more than 100,000 apps in its Windows Store by the end of January, but it's a long, long way from that level right now. Microsoft declined to provide CNET with an updated number but said earlier this month that it had "thousands" of apps available.
Wes Miller, vice president of research at Directions on Microsoft, said earlier this month that there were about 4,300 Windows Store apps at that time. Miller, who monitors the Store total using publicly available information, expects there to be "well over" 5,000 apps on launch day.
5. Even some traditional Microsoft programs won't work with Windows RT. Outlook is one of those, and Windows Media Player is another.
6. You can only get Windows RT already bundled on a device. And that product has to use a processor from Qualcomm, Nvidia, or Texas Instruments. No more "Intel Inside" for these devices. And you won't be able to upgrade your old PC to Windows RT. You'll have to choose Windows 8 instead or buy an entirely new device.
7. Windows RT will have a desktop mode, but it will be restricted to pre-installed, Microsoft-produced software. That includes Microsoft Word, Excel, PowerPoint, and OneNote. You won't see other desktop applications when you visit the Windows Store. Also, if you don't want Office, for some reason, you're out of luck. It comes pre-installed.
8. For business users, Windows RT is less than ideal. All those traditional applications you use won't work, and Windows RT licensing is for home and student use only. That means you have to buy a commercial license to use Windows RT's Office apps for work. And while Office is pre-installed, it doesn't include Outlook.
9. The number of Windows RT devices is pretty limited. Currently, only four companies have plans to launch Windows RT products, and they're all limited to one product each. That has a lot to do with Microsoft's strategy and close supervision over the devices. You'll see PCs and tablets from Lenovo and Asus that run on Nvidia chips, and devices from Dell and Samsung that use Qualcomm processors. Hewlett-Packard and Toshiba, two other companies in the initial program, dropped their plans for Windows RT devices.
10. Overall, Windows RT vs. Windows 8 is pretty darn confusing. Microsoft hasn't done the best job explaining the differences, and many consumers are likely to buy RT only to find out they don't have the full functionality of Windows 8.
Yes, there are some issues with Windows RT that are annoying. But that doesn't mean we hate the operating system. Check back here tomorrow to see why Windows RT might be the right pick for you.