If you use your computer for little more than light Web browsing and email, 2GB of RAM will suffice, whether the system has Windows XP or Windows 7. More RAM will allow you to run more programs simultaneously, and it will generally improve the speed and performance of your machine. Systems today typically come with at least 4GB of RAM, though some small PCs and budget systems may be limited to 2GB or 3GB.
People who like to multitask or play games will want at least 4GB of RAM. If you play graphics-intensive games or do serious video or image editing, you may want to spring for even more RAM--some performance systems include 8GB or even 16GB of memory.
Buying more than 4GB of RAM makes sense only if the system ships with Microsoft's 64-bit Windows 7 operating system; a 32-bit OS will recognize only a little more than 3GB of whatever RAM your system has. If you purchase a new machine, it will probably come bundled with a 64-bit OS, as more retailers move toward including 4GB of RAM. Budget systems are likelier to lean toward a 32-bit OS--but even in this category we've seen a shift to 64-bit. The advantage of 64-bit Windows 7 in a budget system is that if you decide to upgrade your system memory later, the operating system will be able to handle it.
If you intend to upgrade your PC yourself, make sure that your system's motherboard can support additional RAM modules. Check your computer's specs to see how many user-accessible DIMM connectors are available; you'll find this information on a system's technical specifications page. Our how-to guide on installing more memory will help you along the way.
A good case can make your everyday work easier and can simplify such tasks as upgrading and servicing components in a workplace. A well-designed case provides tool-less access to the interior, hard drives mounted on easy-to-slide-out trays, readily accessible USB ports and memory card slots, and color-coded cables for internal and external parts.
The most common cases are minitower and tower designs that use ATX. The ATX specification dictates where the connectors on the back of the motherboard should be (to line up with the holes in the case), and it encompasses details such as the power-supply connector.
Slimline systems and other smaller PCs may use Micro-ATX, which follows the basic ATX specification but includes fewer expansion slots. Mini-ITX is smaller still; Mini-ITX motherboards often appear in small PCs, where they offer quiet, low-power performance (making these systems a great choice for a home-theater PCs).
If you're buying a minitower or tower system, you may have more flexibility in configuring it, whether you want to specify optional components to fill the slots or you want to leave room for future expansion. You should reserve at least a couple of open hard drive bays and a free PCI slot, too. And just as motherboards come in different shapes and sizes, so do case designs.
If you're buying an all-in-one or a small PC, or you're ordering a traditional tower from a major vendor such as HP or Dell, you rarely have much say about your machine's chassis. If the case's size and weight are important to you, try to inspect the machine in a store, or take note of its dimensions when shopping online.
It may be a decade old, but Windows XP remains a stalwart--even on some new systems. Nevertheless, most systems on the market today run Windows 7. Microsoft's latest operating system has received generally positive reviews, improving on many of Windows Vista's foibles.
Microsoft sells six different versions of Windows 7, but only three--Windows 7 Home Premium, Windows 7 Professional, and Windows 7 Ultimate--are available to most desktop buyers. Windows 7 Home Premium, the standard offering, includes the visually appealing Aero Glass UI, plus enhancements to Windows Media Center. Advanced users should consider Windows 7 Professional, typically a $75 to $100 step up; it offers location-aware printing and improved security features that many business users like. Windows 7 Ultimate--which costs about $150 more--is a good choice for power users and business users, thanks to its wealth of networking and encryption tools. Consult a full list of OS features before settling on a particular version.
Once again, if you're running a 32-bit operating system, your computer can use only slightly more than 3GB of RAM, regardless of how much RAM your system carries. So be sure to pick a 64-bit OS; you'll be glad you did when you're ready to upgrade.
Don't forget Windows 8! It's on the horizon now (though still at least a year away), and it promises to be a bold new approach to getting things done with our tech.