Remove old drivers

Remove Old Drivers

To remove old and unused drivers from your Windows computer, first open Start Menu and right-click on Computer and select Properties. From the left side panel, click on Advanced system settings and click on Environment Variables. Alternatively, simply open Control Panel and type Environment Variables.

Now under the User variables box, click on New and type

devmgr_show_nonpresent_devices

in the Variable Name text box & 1 in the Variable Value  box. This will set a flag to allow you to now view unused devices.

You can also use this method to show non-present drivers.

Now type devmgmt.msc in start search and hit Enter to open the Device Manager.

Original: http://www.thewindowsclub.com/how-to-remove-old-unused-device-drivers-in-windows-7