Getting back my DVD drive after missing in XP

I found two related MS KB articles on how to get my DVD drive back after it disappeared in my computer.

• A computer that is running Windows XP cannot detect a USB thumb drive, an Apple iPod, or an external hard disk drive
• You can no longer access the CD drive or the DVD drive, or you receive an error message after you remove a CD recording program or a DVD recording program in Windows XP
  

According to the above, I located the registry key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\
{4D36E980-E325-11CE-BFC1-08002BE10318} and delete the UpperFilters registry value and the LowerFilters registry value. The problem is resolved after restarting the computer and my DVD drive is back.