You may find that none of your compact disc (CD) devices work, including CD-Recordable (CD-R) discs, CDs, and digital video discs (DVDs), and that all the devices are marked with yellow exclamation points in Device Manager.

Back to the top

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base: To resolve this behavior, follow these steps:

1.	Remove or rename the following files in the C:\Winnt\System32\Drivers folder: Cdralw2k.sys Cdr4_2k.sys
2.	Start Registry Editor (Regedt32.exe).
3.	Locate and then remove the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdralw2k
4.	Locate and then remove the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdr4_2k
5.	Locate and then remove the following registry value: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}\LowerFilter
6.	Locate and then remove the following registry value: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}\UpperFilter
7.	Quit Registry Editor.
8.	In the folder where you saved the registry fix file, right-click the file, and then click Merge.
9.	Restart your computer, and then verify that you have access to your CD drives by using a standard audio or data CD.

Back to the top

Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.

Back to the top