Windows Server 2008 SP1 or Windows Vista SP1 multiprocessor systems with some antivirus software may run out of resources (KB961775)

We want to try to get the word out about an issue that has turned into a frequent support call generator for our team here at Microsoft. There is a potential problem on Windows Server 2008 and Windows Vista SP1 multi-CPU systems that have software installed that use Transport Driver Interface (TDI) drivers. Anti-virus software is an example of such software. Many newer anti-virus software versions take advantage of our Windows Filtering Platform (WFP), new for Windows Vista and Windows Server 2008, but some may still rely on TDI. Software that uses WFP will not hit this resource depletion issue.

As this is a resource depletion type of issue, multiple applications can be affected, resulting in widely varying symptoms. We have seen issues with Active Directory user authentication, AD replication, MMC snap-ins for AD, DNS, or DHCP that will not open, general network connectivity issues, and slow or sluggish responsiveness of affected machines.

Our Knowledge Base article about this, 961775, discusses details about the issue and has a link to the hotfix. The problem is resolved in Service Pack 2 for Windows Vista and Windows Server 2008. Obtaining the service pack is the recommended solution.

– Mike Platts