What? Sounds odd but it is true. Having out dated drivers can slow down your computer. So use Slimdrivers or the manufacturers’ website to download the latest drivers. What about devices that no longer exist or software that adds network drivers and you no longer have that driver? These are called ghosted drivers. Windows still loads the drivers and they can cause your system to slow down. A great example of this is Dawn and I removed an old sata driver from a server and the response time increased 10-20%. GhostBuster helps to find these items. This software works off a simple command that is ran from a command prompt and you would later look in the Device Manager to remove the items. This simplifies the process by presenting a GUI to the user and allowing them to remove the items.
For Windows 7, turn off UAC, reboot. Find GhostBuster.exe, right click, properties, compatibility mode, Select Windows XP and run as administrator. Now right click ghostbuster.exe and run as administrator. Find ghosted items. Right Click on a device (select more than one with the Ctrl key). Right click on the devices. Select add device. (this adds the devices to the removal list). Now click remove ghosts.