Windows Explorer is a critical Windows 7 component that consistently runs in the background the moment you boot up your operating system. It uses explorer.exe as the filename and is in charge of the user interface and any folders that you open. Opening too many folders may crash your Windows Explorer, which will then affect your entire Windows 7, causing all other open programs to close or run in an unstable condition. Isolate each folder in its own process to prevent Windows Explorer from affecting the rest of your Windows 7 operating system even if Windows Explorer crashes.
Click the "Start" menu, and type "Folder Options" in the search bar without the quotation marks. Press the "Enter" key on your keyboard to see the dialog.
Click the "View" tab to see a set of check boxes falling under "Advanced Settings." Tick the "Launch Folder Windows in a Separate Process" checkbox.
Click the "OK" button to apply the changes.
You can also bring up the "Folder Options" from the Windows 7 Control Panel in the Start menu.
Though this small tweak will increase the stability of your Windows 7, you may notice a slight performance decrease unless you have more than 2 GB of RAM.