Autorun enables automatic drive detection and than gives you the exact options you can do with that drive, its really good because you automatically gives the best option from your external drive and hence its really easy to use, but there is a downside of Autorun process it automatically injects viruses and malwares
because drive automatically runs with this option.
So if you wanna disable on all drives and other things than you might have to find options in the control panel which may take your time but we have a simple tool to do this work that's Autorun Disabler for Windows 7.
So after you download this amazing small utility from below you simply have to run it and it will ask for the administrator privileges just click on Yes and than you can choose any option to disable Autorun on the drives, well you can even disable on all drives by clicking on the last option i.e : Disable Autorun on all drives, so download this tool from below and have fun.