http://support.microsoft.com/kb/967715
Click Start, click Run, type Gpedit.msc in the Open box, and then click OK. Under Computer Configuration, expand Administrative Templates, and then click System. In the Settings pane, right-click Turn off Autoplay, and then click Properties.
Note In Windows 2000, the policy setting is named Disable Autoplay. Click Enabled, and then select All drives in the Turn off Autoplay box to disable Autorun on all drives. Click OK to close the Turn off Autoplay Properties dialog box. Restart the computer.