Windows Vista and Windows Server 2008 introduced a set of in-box VSS writers that are responsible for various Windows features.

Note  The MSDE in-box writer is not available in Windows Vista, Windows Server 2008, and later. Instead, the SQL Writer should be used to back up SQL Server databases. Only SQL Server 2005 SP2 and later are supported on Windows Vista, Windows Server 2008, and later.

Registry Writer

The registry writer is responsible for the Windows registry. Beginning with Windows Vista and Windows Server 2008, the registry writer now performs in-place backups and restores of the registry. On versions of Windows prior to Windows Vista, the registry writer used an intermediate repository file (sometimes called a "spit file") to store registry data.

In Windows Vista and later, the registry writer does not report user hives.

The writer name string for this writer is "Registry Writer".

The writer ID for the registry writer is AFBAB4A2-367D-4D15-A586-71DBB18F8485.

COM+ Class Registration Database Writer

Beginning with Windows Vista and Windows Server 2008, this writer is responsible for the contents of the %SystemRoot%\Registration directory. The COM+ catalog is a file in %SystemRoot%\Registration with a name that follows the pattern Rxxxxxxxxxxxx.clb, where xxxxxxxxxxxx is a 12-digit hexadecimal number. There can potentially be multiple such files if COM+ applications have been configured on the computer. The file that contains the current COM+ catalog is the file with the largest value of xxxxxxxxxxxx.

The COM+ class registration database depends on a registry key being backed up and hence needs to be backed up and restored together with the registry.

To restore the COM+ Registration Database, a backup application (requester) must call the ICOMAdminCatalog::RestoreREGDB method.

The writer name string for this writer is "COM+ REGDB Writer".

The writer ID for the COM+ class registration database writer is 542DA469-D3E1-473C-9F4F-7847F01FC64F.

MSSearch Service Writer

Beginning with Windows Server 2008, this writer exists to delete search index files from shadow copies after creation. This is done to minimize the impact of Copy-on-Write I/O during regular I/O on these files on the shadow-copied volume.

To install this writer on the server, you must install the File Services role and enable the Windows Search Service.

The writer name string for this writer is "MSSearch Service Writer".

The writer ID for the MSSearch service writer is CD3F2362-8BEF-46C7-9181-D62844CDC062.

WMI Writer

Beginning with Windows Vista and Windows Server 2008, this writer is used for identifying WMI-specific state and data during backup operations. The data includes files from the WBEM repository.

The writer name string for this writer is "WMI Writer".

The writer ID for the WMI writer is A6AD56C2-B509-4E6C-BB19-49D8F43532F0.

Background Intelligent Transfer Service (BITS) Writer

Beginning with Windows Vista and Windows Server 2008, the BITS writer uses the FilesNotToBackup registry key to exclude files from the BITS cache folder. The default cache location is %AllUsersProfile%\Microsoft\Network\Downloader\Cache.

In addition, the BITS writer excludes the following files from backup: the BITS state files (qmgr0.dat and qmgr1.dat), the BITS debug log file, and BITS partially downloaded files.

If the BITS download destination file is an SMB file, the client account must have a trust relationship to the server, or else backups may fail.

The writer name string for this writer is "BITS Writer".

The writer ID for the BITS writer is 4969D978-BE47-48B0-B100-F328F07AC1E0.

Automated System Recovery (ASR) Writer

Beginning with Windows Vista and Windows Server 2008, the ASR writer stores the configuration of disks on the system. This writer reports the Boot Configuration Database (BCD) and is also responsible for dismounting the registry hive that represents the BCD during shadow copy creation. The ASR writer must be included in any backups required for bare-metal recovery. For more information about ASR, see Using VSS Automated System Recovery for Disaster Recovery.

The writer name string for this writer is "ASR Writer".

The writer ID for the ASR writer is BE000CBE-11FE-4426-9C58-531AA6355FC4.

System Writer

Beginning with Windows Vista and Windows Server 2008, the system writer enumerates all operating system and driver binaries. This writer runs as part of the Cryptographic Services (CryptSvc) service. On Windows Vista and later, the system writer generates a file list that contains the following files.

• All static files that have been installed. A static file is a file that is listed in the component manifest with the writeableType file attribute set to "static" or "". Static files include all files that are protected by Windows Resource Protection (WRP). However, not all static files are WRP-protected files. For example, game files are static but not WRP-protected so that administrators can change parental control settings.
• The contents of the Windows Side-by-Side (WinSxS) directory, including all manifests, optional components, and third-party Win32 files.

  Note  Many of the files in the %windir%\system32 directory are hard links to files in the WinSxS directory.

• All PnP files for installed drivers (owned by PnP).
• All user-mode services and non-PnP drivers.
• All catalogs owned by CryptSvc.

The restore application is responsible for laying down the files and registry and setting ACLs to match the system shadow copy. The appropriate hard links must also be created for a system state restore to succeed.

The writer name string for this writer is "System Writer".

The writer ID for the system writer is E8132975-6F93-4464-A53E-1050253AE220.

Shadow Copy Optimization Writer

Beginning with Windows Vista and Windows Server 2008, this writer deletes certain files from volume shadow copies. This is done to minimize the impact of Copy-on-Write I/O during regular I/O on these files on the shadow-copied volume. The files that are deleted are typically temporary files or files that do not contain user or system state.

The writer name string for this writer is "Shadow Copy Optimization Writer".

The writer ID for the shadow copy optimization writer is 4DC3BDD4-AB48-4D07-ADB0-3BEE2926FD7F.

Dynamic Host Configuration Protocol (DHCP) Writer

Beginning with Windows Server 2003, this writer is responsible for enumerating files required for the DHCP server role. This writer is an in-box writer for Windows Server operating system versions; it does not ship in Windows Client.

The writer name string for this writer is "Dhcp Jet Writer".

The writer ID for this writer is BE9AC81E-3619-421F-920F-4C6FEA9E93AD.

File Server Resource Manager (FSRM) Writer

Beginning with Windows Server 2003 R2, this writer enumerates the FSRM configuration files that are used for system state backup. During restore operations it prevents changes in FSRM configuration and temporarily halts enforcement of quotas and file screens. After the restore is complete, the writer refreshes FSRM with the configuration that was restored. This writer is only present when when FSRM (part of File Services role) is both installed and running. This writer is an in-box writer for Windows Server operating system versions; it does not ship in Windows Client.

The writer name string for this writer is "FSRM Writer".

The writer ID for this writer is 12CE4370-5BB7-4C58-A76A-E5D5097E3674.

Windows Internet Name Service (WINS) Writer

Beginning with Windows Server 2003, this writer is responsible for enumerating files required for WINS.

The writer name string for this writer is "WINS Jet Writer".

The writer ID for this writer is F08C1483-8407-4A26-8C26-6C267A629741.

Certificate Authority Writer

This writer is responsible for enumerating the data files for the Certificate Server.

The writer name string for this writer is "Certificate Authority".

Windows XP:  The writer name string for this writer is "Certificate Server Writer".

The writer ID for the writer is 6F5B15B5-DA24-4D88-B737-63063E3A1F86.

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Build date: 10/29/2009