Over time unused, but still installed, drivers can cause problems if they inadvertently become enabled. They can cause hardware conflicts or just cause the system to behave erratically. You can locate and remove any old and unused drivers by enabling a special feature in Device Manager that allows it to display non-present devices.
To configure Device Manager to display non-present devices you will need to add an environment variable DEVMGR_SHOW_NONPRESENT_DEVICES to the Environment Variables dialog box. Begin by, accessing the Start menu, right-click on Computer, and select the Properties command. When you see the System window, select the Advanced System Settings link. When you do, you'll encounter a UAC and will have to deal with it appropriately.
When the System Properties dialog box appears, click the Environment Variables button. When you see the Environment Variables dialog box, you'll see that it contains two panels titled User Variables and System Variables. Environment variables added to the User Variables panel will be available only when that user logs on. Environment variables added to the System Variables panel will be available to all users.
Click the New button. When the New System Variable dialog box appears, type devmgr_show_nonpresent_devices in the Variable Name text box and type 1 in the Variable Value text box.
Then, click OK twice — once to close the New System Variable dialog box and once to close the Environment Variables dialog box.
To view the non-present devices, access the Start menu, right-click on Computer, and select Manage. When the Computer Management window appears, select Device Manager. Once Device Manager is active, pull down the View menu and select Show Hidden Devices. Now, open the various branches in the Device Manager tree and look for device icons that appear translucent or faded.
To remove the device drivers for any of the non-present devices, simply right-click on the faded icon and select the Uninstall command. Once you are done, close Device Manager and restart your system.