Latitude D620 DVD/CD drive not working

My DVD/CD drive randomly disappeared one day. I was unable to find the drive in My Computer and the computer would not read the device when re-installed by taking the device out and re-inserting it. In Device Manager (Right click My Computer>Manage>Device Manager) I could find the drive but it had the warning symbol on the device that it was not working properly. The few things I did to get this to work: Went to a command prompt and typed "regedit" (no quotes) Then went to HKEY_LOCAL_MACHINE > SYSTEM > CurrentControlSet > Control > Class > {4D36E965-E325-11CE-BFC1-08002BE10318} In the right display of the Registry Manager I deleted UpperFilter and LowerFilter by right clicking on the file. Click okay for each deleted file. Exit out of the Registry Editor Go to Dell.com and download the driver R146646.exe Install the driver and run SUPDOS.exe Restart the computer. My drive was instantly recognized and usable. Hope this helps somebody with a LAT D620.