|Open a MS-DOS window and run FDISK and see if it sees the second physical drive and you can switch to it and see the partition information on it.|
If it can, you will have to boot with a Windows ME startup diskette and see if you can run SCANDISK D: on it to repair its file system.
Last hope, is to disconnect the new drive, jumper the old one back to Master by itself and boot with the Windows ME startup diskette and see if you can run FDISK /mbr command on the drive. Then try accessing it with a DIR command.
If that does not work you are going to need some good disk drive recovery tools.