As posted in our forum "...Just thought I would let people know an old bug in Nero has returned. As of Nero 5.5.7.2, if you install any version of InCD after you have upgrade to Nero 5.5.7.2 on Windows 2000, you loose the CDROM/DVDROM and Recorder in your Windows Explorer or My Computer. This is triggered by InCD, but it's a bug in Nero 5.5.7.2. One we had pop up in the past with Nero 5.5.5.1 for some users..." The solution is the same, till we get this resolved in our Nero software.

Open regedit and go to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}

Now delete the keys:
LowerFilters and UpperFilters.

Now reboot and your optical drives should function again.