The Wsusscan.cab file has grown with each new security release. Now, the number of files is approaching the maximum that can be included in a single CAB file. Microsoft is upgrading the internal format of the CAB file to resolve this issue.
All products, tools, and solutions that use the Wsusscan.cab file must be updated by March 2007 to use the new offline scan file. The existing CAB file will continue to be updated and published until March 2007. However, Microsoft will reduce the size of the existing CAB file by removing some security update content.
The Wsusscn2.cab file contains metadata from the following classifications: security updates, update rollups, and service packs.
New versions of the following software are available. These new versions use the new Wsusscn2.cab file.
- System Management Server Inventory Tool for Microsoft Updates (SMS ITMU)
For more information, visit the following Microsoft Web site:
- Microsoft Baseline Security Analyzer (MBSA)
For more information, visit the following Microsoft Web site:
- Windows Update Agent for Microsoft Windows XP, for Windows 2000, and for Windows Server 2003 (all supported processor architectures)
Information for specific customers
If you use Windows Update or Windows Server Update Services but you do not use products that use the Wsusscan.cab file
You do not have to make any changes. The next major release of Windows Update will include the updated CAB file.
If you use SMS ITMU
You must download an updated version of SMS ITMU. This updated version includes an updated Windows Update Agent stand-alone installer. You must deploy the new version of SMS ITMU before March 2007. To download the updated version of SMS ITMU, visit the following Microsoft Web site:
If you use the MBSA 2.0 offline scan feature
You must download an updated version of MBSA and an updated version of the Windows Update stand-alone installer. You must deploy the new versions before March 2007. To download the updated version of MBSA, visit the following Microsoft Web site:
If you use the MBSA 2.0 online scan feature or the MBSA 1.21 online scan feature
If you use MBSA, and you use only the online scan capabilities of MBSA, you do not have to make any changes.
If you use a non-Microsoft solution that uses the Wsusscan.cab file together with the supported WUA public API
You must download the stand-alone installer for the updated WUA on computers that use the supported solution. To download the updated WUA stand-alone installer files, visit the following Microsoft Web sites:
- Windows Update Agent stand-alone installer for 32-bit (X86-based) computers
- Windows Update Agent stand-alone installer for x64-based computers
- Windows Update Agent stand-alone installer for Itanium-based computers
You must modify the solution so that it downloads the updated wsusscn2.CAB file from the following new URL:
There are no changes to the Windows Update Agent public API because of the CAB file format change.
You must deploy the updates before March 2007.
If you use non-Microsoft solutions that read the Wsusscan.cab file directly
You must obtain updated solution software that can read and process the new CAB file format.
Microsoft does not publish the schema to this file because the internal format is subject to change. We do not recommend solutions that read the CAB file directly. However, Microsoft has provided information about the format changes to any customer or to any solution provider that has an existing solution.
For more information, click the following article number to view the article in the Microsoft Knowledge Base:
927745 Detailed information for developers who use the Windows Update offline scan file
For more information, join the WU Offline Scan public forum, or contact Microsoft Product Support Services.
You must deploy these updates by March 2007.
Updates to this article
We will update this article when there is any new information about these releases.