Toshiba DVD Problem

I have just bought a Toshiba SD-M1402 DVD-ROM and fitted in a DAN Pentium II machine. The machine dual boots with Windows 98 and Windows 2000. Neither operating system will ‘see’ the DVD. As Windows 2000 boots the orange LED shines, and I can insert a DVD -CD. However as the system initialises the light goes out and I cannot see and CD/DVD in Explorer.
The fitment was just a simple replacement for the previous CD. I have not altered the factory Default Jumper settings.
Your help would be greatly appreciated.