Computers are in transition: Technologies such as the PCI Express bus and all-digital video connectors are supplanting their predecessors. More important, Microsoft's new Windows Vista is right around the corner. Anyone who's thinking of buying PC hardware in the next few months must keep an eye on the future.

If the transition to Windows XP is any lesson, the biggest potential hassle of a Vista upgrade is lack of support for legacy hardware and peripherals. Before moving to the new OS, check with your printer, scanner, and other peripheral manufacturers to learn whether they plan to offer Vista drivers for your product.

To help ease the move, Microsoft has created the Windows Vista Upgrade Advisor, a free program that examines your system's hardware and attached peripherals to identify possible driver and hardware conflicts, as well as other compatibility problems.

If you're ready to buy a PC now, with an eye toward upgrading to Vista down the road, stick to a Vista Premium Ready machine rather than choosing one that supports only Vista Basic (be sure to see Microsoft's description of the various Vista releases). And no matter which version of Vista you plan to run, don't buy any less than 1GB of RAM.

The following tips will help you get the most out of your hardware--current and future--for many years to come.

Leave room for RAM: Make sure that you have space for future memory upgrades. Your new PC should have at least one free RAM socket (check with the vendor to determine expandability options for systems with dual-channel memory setups). Also, leave some room for expansion when you upgrade: Don't install two modules if you can get the same amount of RAM on one. Always consult your motherboard manual before buying memory, however, as some systems require that the RAM modules be installed in pairs.

Avoid PCI cards: If your machine has both an open PCI Express slot and a PCI slot available, use a PCI Express card rather than its PCI equivalent for such internal components as a wired or wireless network adapter. If PCI Express isn't an option, add an external USB 2.0 version of the device. It may cost a bit more, but USB devices are easy to transfer to other computers, and USB should be around long after the PCI bus is history.

Choose SATA, not PATA: Make sure that your new PC has at least two Serial ATA connectors. Some budget systems offer only older Parallel ATA connectors, and others come with a single SATA slot. If you're adding a new internal hard drive, make it a SATA drive, which is easier to install, has slimmer cabling to help cooling air circulate in the case, and can be transferred to future PCs, which are likely not to have PATA connectors at all.

If your current system lacks a SATA connector, use Addonics' $30 Serial ATA to IDE converter to link a SATA drive to your IDE port. Or add multiple SATA ports via Adaptec's $80 DuoConnect 5020 PCI card (see FIGURE 1), which includes two SATA ports and five USB 2.0 ports. Always get the highest-capacity drive you can afford; eventually you'll use the space. Microsoft requires a whopping 15GB of free disk space just for Vista.

Go digital: Some hard-core gamers still prefer the quick response and clarity of analog CRT displays, but most users today want an LCD equipped with an all-digital connection through a DVI port. If you're buying a new monitor or graphics card, check that it provides a DVI connection. If necessary, use VGA-to-DVI and DVI-to-VGA adapters (available at any computer store for less than $10) to support your current hardware.