When you deleted the OS, you deleted the native support that Windows provides for optical drives. When you have no Windows os installed and running, you have no support for optical drives. In order to enable the optical drive, you must use a dos driver. All Windows 98SE boot disk contain the universal dos driver oakcdrom.sys along with the dos MSCDEX.EXE. These 2 drivers will enable ANY atapi compliant drive. And the Windows 98SE installation disk will also enable any atapi compliant drive as long as the system bios supports booting from an optical drive. You must enter bios setup and change the boot order where the optical drive is the first boot device. If your bios doesn't support booting from optical drive, then boot using the bootdisk. It will enable your drive if you have the drive connected properly, configured properly, and connected to the secondary ide port and as long as you have the bios settings correct.