Windows only: When you upgrade your video card—or even just the drivers—the old version leaves settings and registry entries cluttering up your system—but you can clean them up.
Driver Sweeper works by removing all the extra stuff that the driver uninstaller leaves behind—so you'll need to first uninstall the video card, motherboard or sound card drivers, and then run the utility to remove all the extra traces. Once you've done so (and rebooted), you can proceed with installing the newer drivers. It's one of those really useful utilities that isn't necessary for most people—in fact, not recommended for the less tech-savvy—but a critical tool that I've used whenever I do an upgrade.
Driver Sweeper is a free download for Windows only. If you have a device that isn't supported, or want to remove drivers the built-in Windows way, I've previously written an article on how to boost performance by removing old drivers after upgrading to new hardware.