I had this error right after I downloaded or updated the Vista SP1 from Windows Update. Luckily, the steps below worked for me. Before you try to follow these steps, first, read carefully the instructions. I have added snapshots of how your window will look like at every step. To get the overview of the Code 39 Error, try to read this link, where I got the steps: http://support.microsoft.com/kb/929461/en-us or download the printable .pdf file at Error_Code39_Microsoft_Steps.
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 this link: http://support.microsoft.com/kb/322756/ or download the printable .pdf file at Backup&Restore_Windows_Registry.
To resolve Error Code 39, remove the affected filter drivers. To do this, follow these steps:
1. CLICK START button, TYPE regedit in the Start Search box, and then click regedit in the Programs List.
*If you are prompted to for n administration password or confirmation, type your password, Or click Continue.
2. Locate, and then click the following registry subkey:
Caution: There can be many instances of the registry subkey that is mentioned in step 2. You must make sure that you are in the appropriate registry subkey before modifying the UpperFilters and the LowerFilters values as in step 3 below. To verify that you are in the appropriate registry subkey, make sure that the default data value is DVD/CD-ROM and the Class data is CDROM.
3. In the right pane, right-click UpperFilters, and then click Delete.
4. Click Yes to confirm the removal of the UpperFilters registry entry.
5. In the right pane, right-click LowerFilters, and then click Delete.
6. Click Yes to confirm the removal of the LowerFilters registry entry.
7. Exit Registry Editor, and then restart the computer.
Note: After you remove the UpperFilters and LowerFilters registry entries, you may lose functionality in certain programs such as CD recording programs. In this scenario, you must reinstall any affected programs. If the problem recurs, contact the program vendor to determine whether an update is available for the program.
For information about how to contact computer software vendors, click the appropriate article number listed in http://support.microsoft.com/kb/929461/en-us to view the article in the Microsoft Knowledge Base.