Hotfix KB979917 affects SharePoint Server 2010

FYI: Pay attention to Windows Server 2008 hotfix KB979917 , this hotfix can be required if you are using web applications with CLAIMS as authentication provider, you can see the following message " The Health Analyzer reports that web applications using claims authentication require an update to fix potential security risks. This is described in the KB article KB979917 that the hotfix can be obtained by contacting Microsoft Support. "

Before to apply this hotfix directly on production SharePoint farms update SharePoint to February 2010 CU and test it. If you are not using CLAIMS over SharePoint do not apply the hotfix on SharePoint servers, specially if this is not required.

You will probably see the following messages on event viewer application logs:

Search crawl component index path error - Events 2589 (SharePoint Server 2010)

Search gatherer disk is full - Event 23 (SharePoint Server 2010)

Search database out of space - Event 52 (SharePoint Server 2010)

Search indexer initialization index failed - Event 71 (SharePoint Server 2010)

Search indexer low disk space - Event 80 (SharePoint Server 2010)

Search administration component failed - Event 121 (SharePoint Server 2010)

Note: Search issues could be faced after applying the fix.