Microsoft, along with a host of other security updates, turned off AutoRun with a patch released on Patch Tuesday. AutoRun was the functionality that allowed programs to run directly when CDs, DVDs or USB drives were inserted.
AutoRun was removed in order to curb security threats that abused the function. According to Holly Stewart from the Microsoft Malware Protection Centre, five of the top ten most popular malware families used the AutoRun function to proliferate. It wasn’t the only trick they used, but it certainly was the method that led to the most number of infections. Windows 7 has AutoRun turned off natively, and XP and Vista have finally caught up.
However, there are a lot of people who like the AutoRun feature, so Microsoft are also including a FixIt that will reverse the update.