When windows XP launched, some PCs and peripherals wouldn't work with the new OS because device drivers had not yet been written. The same is true for Vista. Whether you plan to install Vista on your current PC, or to buy a Vista-equipped system to use with your existing peripherals, these tips will help smooth the transition.

Study up beforehand: To run the bare-bones Vista Home Basic, Microsoft recommends a CPU running at 1 GHz or faster, plus 512MB of RAM and 15GB of hard-drive space. Home Premium, Business, and Ultimate editions with the new Aero environment require at least 1GB of RAM, and for systems without integrated graphics, a DirectX 9-capable graphics processor with 128MB of its own RAM, DirectX 9, and a few other features. Read Microsoft's Vista System Requirements.

Microsoft's Vista Upgrade Advisor scans your PC to determine which editions of Vista will run on it, and which of its hardware components are incompatible with Vista. When I ran Upgrade Advisor on my year-old machine, the program found no compatibility problems--but it did list ten components for which it had no data, including the PC's USB port. You can also check Microsoft's Hardware Compatibility List, or the Vista hardware list on IeXwiki. Need to identify what components are in your system? The free Belarc Advisor utility will quickly scan your PC and identify all its hardware.

If Vista doesn't support one of your PC's components, look for updated Vista drivers on the vendor's Web site. If you can't find them, the drivers may still be in development--so ask the company about it. RadarSync, a device driver update service, has created a list of links to Vista drivers.

After you have identified which drivers lack Vista equivalents, copy the XP versions to a CD or anyplace you can easily access them once you've installed Vista. Make sure you have your network drivers handy so you can go online and download other device drivers and updates.

Be prepared for trouble: Back up your old XP installation to a second hard drive or to a different partition on your main drive so you can revert to XP if something goes wrong with Vista. (What can go wrong? One possibility: A PC World editor found that, after installing Vista on his home PC, he could no longer log in to the office network because no Vista version of the Cisco VPN client existed.) As an alternative to doing a complete backup on a separate hard drive, use a drive-image program such as the $40 Acronis True Image 10 to burn an image of your XP installation onto recordable DVDs.

Or set up your PC to dual-boot. Find instructions on installing both XP and Vista on a dual-boot PC.

Once you've installed Vista, open Device Manager to check for problems: Right-click the Computer icon and choose Manage, Device Manager. Nonfunctioning devices are flagged with an exclamation point in a yellow triangle (click on thumbnail image at left to see an example). If Windows can't find a driver, it may list the device as 'Unknown Device' under 'Other devices'. HunterSoft's free Unknown Device Identifier utility helps you find the name of the mystery hardware.

Send your tips and questions to kirk_steers@pcworld.com. We pay $50 for published items. Kirk Steers is a PC World contributing editor and the author of PC Upgrading and Troubleshooting QuickSteps from McGraw-Hill,Osborne Press.