A recently updated device driver fails.
Windows XP is smart enough to remember driver changes and provides an automatic way to roll back to the previously installed driver. Rolling back to a previous driver can save you a great deal of time and frustration, if you are aware of the specific change you made to your hardware. If the device driver update you did fails completely, preventing you from using the system, then you may have to perform this step in Safe Mode or use Recipe 3.5 to get the system back to a previous state. Windows System Restore is an alternative solution that will roll back more than just your hardware configuration, since it rolls back all software and Registry changes as well.
Driver rollback is a feature unique to Windows XP and will likely be in future versions of Windows. Microsoft is generous about its coverage of this feature in sev-eral knowledge base articles, including those found at http://www.microsoft.com/windowsxp/pro/using/itpro/hardware/driverrollback.asp, MS KB 83922, "A device does not work after you try to update the driver by using Windows Update"; http://www.microsoft.com/windowsxp/compatibility, http://www.microsoft.com/windowsxp/using/helpandsupport/learnmore/russel_02october14.mspx, and http://www.microsoft.com/windowsxp/using/setup/expert/mcfedries_03may12.mspx.