Greg, a graphic artist, installs a new art application on his Windows 7 computer. The application prompts Greg to install an updated video driver, which is unsigned. Greg accepts the unsigned driver and completes the installation. Greg uses the system for several days, and then reports that his display doesn't seem to refresh properly under some conditions. You want to configure Greg's computer to use the previous video driver until the manufacturer provides a signed driver, but he still needs to be able to use the application he installed. What should you do?