Dubbed Windows RT, the ARM version looks just like regular Windows, but with one gigantic caveat: no backwards compatibility. In other words, you can't download and install classic desktop apps in Windows RT. You can only run full-screen Metro apps from the Windows Store.
If you're coming from XP, you probably don't want to get stuck with a device that operates almost exclusively in Microsoft's modern UI (though Windows RT does offer a desktop version of Internet Explorer as well as baked-in desktop Office apps).
Fortunately, Windows RT is designed for use on tablets such as the Lumia 2520 and the Surface 2, so being fooled by RT shouldn't be an issue if you're looking only at traditional PC form factors. Keep an eye out if you're considering a "hybrid" that switches between laptop and tablet form factors, however, or if you're buying a Windows tablet with plans to pick up a supplemental keyboard.
Solid state of mind
There are two kinds of onboard storage drives you can get with PCs these days: standard hard disk drives (HDD) and solid-state storage (SSD).
If you're looking to get as much storage space as you can then you'll want a PC with an HDD. Hard drives haven't changed a ton in recent years. They're just faster, more reliable, and far more spacious than they were in the early days of XP.
But if you're looking to make your PC feel like greased lightning, then you'll want to look at a device with SSD. Seriously: An SSD is the most noticeable upgrade you can make with a PC, speeding up everything from boot times to application loading to file transfers speeds. If you've never used a PC outfitted with an SSD, the first time almost feels like magic—but what you gain in speed, you lose in affordability and storage capacity.
A PC with an SSD will generally be more expensive than a device with an HDD, and most affordable devices loaded with SSDs max out around 256GB of built-in storage, though larger drives are available.
Windows 7 vs. Windows 8.1
We saved the biggest for last. Depending on the shops you visit, you may be confronted with two choices for your next PC: Windows 7 or Windows 8.1.
While Windows 7 will be more familiar to XP users than Windows 8.1, it can also be more expensive to get a Windows 7 PC at this point, since they're less common now and most often found in business-class machines.
But if personal comfort is more important than saving a few bucks, Windows 7 may be worth it. Keep in mind, however, that Windows 8.1 is what Microsoft is banking its future on. As of right now, it will have a longer support time than Windows 7, and some of the more familiar aspects of Windows, such as the Start menu, are headed back to Microsoft's latest version of Windows. Plus, as I said earlier, Windows 8.1 is a better desktop PC than Windows 7—as long as you banish the Start screen, that is.
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