How to remove old drive devices from Win7 system

1. First right click on the “Computer” icon on the win7 desktop, select “Properties” in the menu;

2, then click on the left side of the open panel “Advanced System Settings ”, in the pop-up system properties dialog box, click the "Environment Variables" button under the "Advanced" tab;

3, the user variable in the upper part of the "XX" & rdquo Click there <;New” button;

Enter the variable name: devmgr_show_nonpresent_devices
Enter the variable value: 1, and finally click the <;OK” button.
4, then right click on the "Computer" icon on the desktop, select the "Manage" option, and then click on the left to open "Device Manager";;

5, in the device Manager's menu bar, select “View---Show hidden devices”options;

6, then you can find "Other devices" on the right side of Device Manager, then You can right-click and select Uninstall in the unused "Unknown device".