Your backup program may fail or incorrectly exclude some files from your backup in Windows XP

Your backup program may fail or incorrectly exclude some files from your backup after you install the Background Intelligent Transfer Services (BITS) version 2.0 update.

For additional information about this update, click the following article number to view the article in the Microsoft Knowledge Base:

This problem occurs if the BITS 2.0 service starts after you install update 842773. BITS 2.0 writes the BITS_Metadata entry to the following registry subkey: Values in the FilesNotToBackup registry key are used by various backup programs to determine what files must be excluded from your backup and then recovered. BITS 2.0 creates the BITS_Metadata entry in this registry key to make sure that recovering from a backup will not affect the ability of BITS 2.0 to resume a file transfer after an unexpected disruption.

The the BITS_Metadata entry that BITS 2.0 writes to the FilesNotToBackup registry key is not correctly formed. Specifically, the the BITS_Metadata entry that BITS 2.0 creates is in multi-string value (REG_MULTI_SZ) format. This format requires two NULL characters at the end of the value data. However, BITS 2.0 terminates the the BITS_Metadata entry data with one NULL character that is followed by an 0xFEEE unicode character. In some cases, this malformed value causes your backup program to fail or to inaccurately interpret the file path to exclude from your backup.

To resolve this problem, download and then install the following update.

The following file is available for download from the Microsoft Download Center:

Download the WindowsXP-KB883357-x86-enu.exe package now. (http://www.microsoft.com/downloads/details.aspx?FamilyId=8DBCAE14-2DAC-4445-91EC-54C042AD6729&displaylang=en)

Release Date: August 13, 2004

For more information about how to download Microsoft support files, click the following article number to view the article in the Microsoft Knowledge Base: Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help prevent any unauthorized changes to the file.

This update modifies the BITS 2.0 service so that it verifies that the registry value that is described in the "Cause" section is present and that the registry value is in the correct format. The BITS 2.0 service rewrites the registry value if it is required. This behavior occurs every time that the BITS 2.0 service starts.

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 work around this problem, modify the registry to create the correct registry value. To do this, follow these steps.

1. Click Start, click Run, type cmd, and then click OK.
2. Type the following command, and then press ENTER:
   Reg.exe ADD HKLM\System\CurrentControlSet\Control\BackupRestore\FilesNotToBackup /v BITS_metadata /t REG_MULTI_SZ /d "%ALLUSERSPROFILE%\Application Data\Microsoft\Network\Downloader\*" /f

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

For more information about BITS, click the following article number to view the article in the Microsoft Knowledge Base: