If I'm working on one of the computers I use just for testing, I'll click "install anyway" and wait to see what happens. Most of the time, it works fine. Sometimes, the new program doesn't work, but the rest of the computer is fine. Occasionally, the new software really makes a mess of my computer, as in the case of a Nortel virtual private networking client that left me unable to connect to any networks.
MISPLACED SUSPICIONS. There's bad news and good news in this picture. The bad news is that seven months after Microsoft shipped XP, many vendors still haven't gotten their software properly certified. The good news is that Windows XP has some built-in damage control that lets you risk installing uncertified software -- and still have a very good chance of restoring a working configuration if something goes wrong.
Although the certification program was controversial when the software giant first announced it as part of Windows 2000 -- critics saw it as more evidence of a Microsoft plot to take over the world -- it's actually a very good idea. One of the reasons that Windows 2000 and XP are so much more crash-resistant than the Windows 95 family is that programs are prevented from having direct access to the hardware. But a special type of privileged software, called a driver, serves as a link between a program and devices such as printers, network cards, or digital cameras. Bad drivers can bring down any operating system, so to improve stability, Microsoft required that such code pass a suite of tests administered by Windows Hardware Quality Labs.
Microsoft and independent software and hardware vendors complain that the certification process takes too long and that Gates & Co. gave them with a moving target. Microsoft avoids criticizing the vendors. Asked about the slow pace of driver certification, senior XP product manager Greg Sullivan recently said only that he's pleased vendors seem to be catching up. For example, by the end of April, Hewlett-Packard had finally completed driver certification for all the inkjet printers it intends to qualify for XP (drivers for some older inkjets will not be updated -- click here to visit H-P's Web site for more information.)
What should you do if an installation presents you with a certification warning? It depends. If the manufacturer claims certification for Windows 2000 but not XP, the odds are very good that it will work anyway. If only Windows 95/98/Me compatibility is claimed, it probably won't work and may seriously destabilize your system.
SAFETY NET. Fortunately, however, Microsoft has provided some insurance, called System Restore, that allows you to undo any damage by restoring your computer to its previous condition. Before you install anything dubious, click on the Start Menu and select All Programs, then Accessories, System Tools, and System Restore. Choose "Create a restore point," and follow the directions. (A restore point should be set automatically when you begin the installation, but why take chances?)
Once the installation is complete, test the new program. If it doesn't work or causes your computer to behave strangely, repeat the process but select "Restore my computer to an earlier time" and pick the restore point you created. This not only uninstalls whatever you've just added but, unlike the Windows Add/Remove Programs control panel, it also restores any files that were replaced during the installation. I have had to use System Restore many times, and it really works. You should still be careful about what you install on your PC, but it's nice to know that rescue is available. Wildstrom is Technology & You columnist for BusinessWeek. Follow his Flash Product Reviews, only on BusinessWeek Online