Replace the original DVD ROM drive

I have an Inspiron 4000 laptop.  The original DVDROM drive was faulty according to our IT person at work.  I ordered a replacement from Dell.  It is the exact same part, but when I slide it into place, the computer does not recognize it (drive not shown under "My Computer" and drive door will not open).  When I put the old drive back in and restart the computer, the "D" drive is back (only with a faulty DVDROM drive)

What needs to be done to get the computer to recognize the new drive?  I tried to run "detect new hardware" trough windows 98 but it did not pick it up either?