You can Enable/Disable the autoplay settings for each CD/DVD device in Windows 9x by following these steps:
1) Open the Control Panel - Click on Start -> Settings -> Control Panel.
2) The Control Panel will open up. Double click on the System icon.
3) The System Properties window will open up. Click on the second tab labeled Device Manager. Expand the CD-ROM group and you will notice all of your CD/DVD devices listed here. Select the device that you would like to configure and press the Properties button.
4) The properties window for that device will now open up. Click on the Settings tab. You will notice a box labeled Auto insert notification. If this box is checked then autoplay will be enabled for this device. Uncheck this box to disable autoplay. Press OK to close this window.
You may need to reboot your computer in order for the changes to take effect. You can also use the free AutoPlayConfig program to enable/disable autoplay.