Trouble with DVD to CD drive refit.

System is Pentium2 300MHz. Win 95.

CD Rom was removed to make room for Panasonic DVD drive, The DVD drive refused to open at all (both software and the front panel button). This problem persisted, even in DOS the panel button wouldn't work. Returned drive to supplier.

Reinstalled CD drive, only to find that it would not open through the software eject. Panel button works, although the software always reads the tray as open and only gives option to close.

Device manager detected both drives happily on startup. On reinstalling the CD, windows did not detect new hardware.

When trying to acces the drive get a 'drive not ready' error message.

Any ideas other than remove the CD from device manager?
Is there any way to get rid of any DVD drivers that have hidden themselves away?