How to remove stale driver devices in Windows 7

Some people don't care about the old drive devices in Windows 7, but if you find that some recently installed devices are not working properly or often cause the computer to crash, then you can consider deleting old or unused device drivers in Windows 7. .
1. Right click on the Win7 desktop & ldquo; computer & rdquo;, select “ attributes & rdquo;.
2. In the left panel, find “Advanced System Settings” and click “"Environment Variables> at the bottom of the “Advanced” tab.
3, in the upper part of the "XX user variables" where click "ld"; new & rdquo;
input variable name: devmgr_show_nonpresent_devices
input variable value: 1, and finally click "ld"; OK & rdquo ; button.
4. Right-click on the desktop & computer; "Computer”, select “Manage" on the left to open “Device Manager”.
5. In the top menu bar of the device manager, select “View”——“Show hidden devices”.
6, so you can find "Other devices" on the right side of the device manager.
7, right click does not use "unknown device", uninstall it!