BBC.com reports that Microsoft has admitted that some speech-recognition features of its Vista operating system could in theory be hijacked so that a PC could tell itself to delete files. The new operating system can respond to vocal commands, raising concerns about malicious audio files on web sites or sent via eMail.  Some users described a scenario where users of an audio file of voice instructions was used to tell the computer to delete documents.  However, Microsoft said that the exploit was possible, but for it to work, the voice-recognition feature would need to be activated and configured and both the microphone and speakers would have to be turned on…

http://news.bbc.co.uk/2/hi/technology/6320865.stm