Delete UpperFilters and LowerFilters Registry values

The first thing you need to do in the Registry is to delete the UpperFilters and LowerFilters Registry values. Registry values are listed under Registry Keys and these values contain instructions for your Windows installation. You should take a backup of your system and Registry file before making any changes.

As a brief explanation, UpperFilters go between the Operating System and the relevant Driver, and LowerFilters go between the Driver and the relevant hardware (such as CD-ROM drive). These problems are usually associated with DVD and CD-ROM Drives.

1. Select Start > (in Windows XP then select Run)
2. In the Search box (or Run box in XP) type in regedit and click OK
3. In the Registry Editor find the HKEY_LOCAL_MACHINE folder under My Computer and click the + icon to expand
4. Using the + icon to expand folders, scroll to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class
5. Under this folder you should see a series of subkeys which are 32 digits in length
6. Use the GUID Subkeys list below to ascertain which Global Unique Identifiers (GUID’s) relate to your problem
7. Once you have found the GUID relating to the problem device, click the registry subkey corresponding to this GUID
8. You can now locate the UpperFilters and LowerFilters values in the window on the right (you may only see one of these)
9. Right Click on UpperFilters and select to Delete
10. Choose Yes to the prompt “Deleting certain registry values could cause system instability. Are you sure you want to permanently delete this value?”
11. Do the same as above for LowerFilters (ignore any values with .bak extension)
12. Close Registry Editor and restart your computer

GUID Subkeys
4D36E965-E325-11CE-BFC1-08002BE10318 – CD/DVD/Blu-ray drives
4D36E967-E325-11CE-BFC1-08002BE10318 - Hard drives
4D36E968-E325-11CE-BFC1-08002BE10318 - Video adapters
4D36E96A-E325-11CE-BFC1-08002BE10318 - Hard drive controllers
745A17A0-74D3-11D0-B6FE-00A0C90F57DA - Some USB devices
6BDD1FC1-810F-11D0-BEC7-08002BE2092F - IEEE 1394 host controller
6BDD1FC6-810F-11D0-BEC7-08002BE2092F - Cameras and scanners
4D36E96B-E325-11CE-BFC1-08002BE10318 - Keyboards
4D36E96D-E325-11CE-BFC1-08002BE10318 - Modems
4D36E96F-E325-11CE-BFC1-08002BE10318 - Mouse devices
4D36E96C-E325-11CE-BFC1-08002BE10318 - Audio and video devices
4D36E972-E325-11CE-BFC1-08002BE10318 - Network adapters
4D36E978-E325-11CE-BFC1-08002BE10318 - Serial and parallel ports
4D36E97B-E325-11CE-BFC1-08002BE10318 - SCSI and RAID controllers
36FC9E60-C465-11CF-8056-444553540000 - USB host controllers and hubs