If autoplay CD-ROM's to not start automatically do the following:

1. Hold down the Windows Key and press Pause/Break key to open System properties.
2. Select Device Manager tab
3. Click on the plus sign next to CD-ROM and double click on the on the CD-ROM device.
4. In CD-ROM properties click on the settings tab and ensure the Auto Inset Notification box has a tick in it.

If this is already ticked then a setting in the registry needs to be changed.
Close down the properties box and system properties.

Edit registry as follows:

1. Click Start > Run and in the open box type regedit then click OK
2. Navigate to the following key
   
   HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
   
   
3. Modify the value for the NoDriveTypeAutoRun key to 0000 95 00 00 00
   
   
4. Close registry editor then restart your computer.