Autoplay or autorun is the ability of a modern operating system on a computer to automatically perform an action when different removable media devices are inserted into a computer system.Autorun is intended to be a convenience for the computer user in various different situations, such as when a software CD is inserted into the computer and the installation menu for that CD automatically gets displayed on the computer screen. However, this can also cause many security concerns in situations where a computer user does not expect a software installion to start automatically or does not want the software to install on their computer system. For example, someone that wants to attack a certain computer system could easily walk by with a CD or other media that could easily be inserted into the computer without drawing much attention. This media could be setup to autorun a software installation that could be potentially damaging to the computer system it is installed in. In other situations, a CD could contain malicious software and be distributed to computer users that do not expect software to be on the CD at all. There have even been situations in the past where music CD’s from well known labels have not always been safe for use in a computer system because of the autorun feature.

If you are concerned about the autorun feature of a CD or other media, it can easily be bypassed by holding down the shift key when you insert the CD into your computer. It can also be diabled permanently by setting the Autorun registry key to 0. Unfortunately if the autorun feature is disabled, clicking on the CD-ROM drive in my computer will still activate the autorun feature of that CD.

Autoplay, which is a slightly different feature in the Microsoft Windows operating system is used to automatically play an audio CD in Windows Media Player once it has been inserted intot he computer. It also will display the contents of a disc in Windows Explorer if the files on that CD are not audio files. This feature can also be disabled like the autorun feature. In order to disable autoplay in Windows XP the computer user needs to simply go to a tab labeld AutoPlay in the drive properties window and select which of the four different behaviors they would like to use. The different options include play, open folder to view files, take no action and prompt me each time to choose an action. This method of changing the settings however will only work if the drive you are trying to set is permanently mounted. This means it will not work from removable storage such as a USB MP3 player.

If you need to disable autoplay from running on removable storage devices, this can be done using TweakUI, which is a utility developed by Microsoft for editing various parts of the operating system. This program is abailable for download online. Once you have the program running, select My Computer, Auto-Play then Drives to disable all the drives from using the autoplay feature.