NEW YORK ( TheStreet) -- Your aging computer has finally called it quits -- or it's so sluggish you just want to put it out of its misery. And chances are, it's been awhile since you shopped for a PC, though you frequently upgrade your smartphone and, of course, you have an iPad or other tablet.Well, computers have changed just a bit. Ultra-light portables (sub 4-pound laptops), nettops (mini desktops) and convertibles (touchscreen laptops that flip into tablets) are bringing it. Everything's a little bit faster, bigger or thinner. Solid-state storage drives are widely available. Same with Blu-ray drives, USB 3.0 ports and HD Web cams. Microsoft's (MSFT - Get Report) Windows 8 launched last fall, Apple's (AAPL - Get Report) OSX Mountain Lion debuted last summer. There's also Google's (GOOG) Chromium.
But PC sales are declining and it's not just because of perceived cannibalism from the iPad, Kindle Fire and tablet market. It's because people are holding on to computers longer because there has been little to motivate new purchases. Still, if you need a new computer, here's a primer (and reminder) of what mainstream shoppers should look for: The screen: Screen size and quality are one of the biggest motivators to buy a new laptop, says Steve Baker, with market research firm NPD. If you want HD movies to look good, get an HD screen. Look for 1600x900 or 1080p resolution. Apple's Retina Screens, at 2880x1800, are the high end. Also, consider shrinking the screen size. While 15.6-inch is still the most popular, 13-or-14-inch screens keep laptops lighter. If you're looking for anything larger than 15, consider an all-in-one computer, which has larger screens and are lighter than traditional desktops. The other new screen feature is touch. Right now, though, there's a bit of a glass shortage so touchscreen laptops are not prevalent. The operating system: Whether you're a Mac or PC, that debate has nearly become irrelevant. Both sides feel the pain of declining PC sales. But what you do on either system is way easier today, thanks to Cloud-based services. It doesn't really matter which OS you use to check email, store files, share Tweets, add Facebook (FB) "Likes," or even edit photos and play games. Companies like Microsoft and Adobe (ADBE - Get Report) now offer their Office and Photoshop software as subscription services that are OS agnostic and can be installed on multiple computers. "In general, the Web is most people's software and that's pretty agnostic," said Baker, with NPD.