By default, Autoplay feature is disabled in Windows 7.
How to Enable Autorun for Removable Media in Windows 7:
1.In Windows 7,Click the Start Button and select the control panel. Make sure that control panel open up under the default view.
2.You should actually click on “Hardware and Sound” --> the “Autoplay” options on the next screen.
3.At the top, check "Use Autoplay for all devices" and Click Save button.