Windows Server Update Services (WSUS) Classifications

We recently noticed a situation where our clients systems were not getting Daylight Savings Time (DST) or Windows Malicious Software Removal Tool updates. After researching I found that Microsoft classifies some updates as Update Rollups in WSUS.

  • Cumulative Security Updates for ActiveX Killbits
  • Updates for Intelligent Message Filter for Exchange
  • Daylight Savings Time updates
  • Windows Malicious Software Removal Tool

So, you must  select Update Rollups in order to have them available in WSUS.  For any given product or product family, updates could also be available among multiple classifications (for example, Windows XP family Critical Updates and Security Updates).

The following table lists examples of update classifications: [more]

Update ClassificationsDescription
Connectors Software components designed to support connection between software.
Critical updates Broadly released fixes for specific problems addressing critical, non-security related bugs.
Development kits Software to aid the writing of new applications that usually includes a visual builder, an editor, and a compiler.
Drivers Software components designed to support new hardware.
Feature packs New product functionality usually included in the next full product release.
Guidance Scripts, sample code, and technical guidance designed to help in the deployment and use of a product or technology.
Security updates Broadly released fixes for specific products, addressing security issues.
Service packs Cumulative sets of all hotfixes, security updates, critical updates, and updates created since the release of the product.

Service packs might also contain a limited number of customer requested design changes or features.
Tools Utilities or features that aid in accomplishing a task or set of tasks.
Update rollups Cumulative set of hotfixes, security updates, critical updates, and updates packaged together for easy deployment.

A rollup generally targets a specific area, such as security, or a specific component, such as Internet Information Services (IIS).
Updates Broadly released fixes for specific problems addressing non-critical, non-security related bugs.

Networking Security and Compliance WSUS