Microsoft is aware through recent customer feedback, that many of its enterprise customers have been experiencing performance issues when they apply Microsoft updates to certain workstations or servers. Customers are experiencing this when they use SMS 2003 SP1 or a later version with the Inventory Tool for Microsoft Updates (ITMU) and on computers that are running the Windows Update agent. The performance issues are causing high levels of CPU consumption when a scan is performed or when Microsoft updates are being applied.

Microsoft is aware of the issue and is focused on reconciling the issue for customers. As soon as it was known that customers were experiencing performance problems, the issue was escalated through the appropriate channels across Microsoft. There is no known resolution at this point. But Microsoft is working hard to provide one.

Until a definitive resolution is reached, enterprise customers experiencing performance spikes should take the following steps to help alleviate the problem:

1.	For managed clients, whenever possible, schedule updates outside business hours to minimize impact to Information Worker productivity.
2.	When you deploy updates, we recommend that administrators send out an advertisement to end-users that is configured to let the users know that updates are currently being applied. That way, users may infer that the computer could be slow to respond because of this activity. Also encourage end-users not to turn their computers off if they experience a performance issue so that the updates can be applied correctly.
3.	For managed servers, schedule updates when server utilization is low.
4.	For ongoing health checks, where applicable, reduce your scan intervals to one time per week.

Microsoft is working to provide a resolution. The investigation into the issue is ongoing and is a top priority.

The ITMU tool was released last year and is designed to help customers update their managed systems replacing a multitude of legacy scan tools with a with a single scan tool. The tool shares the same security update, update rollup, and service pack data as offered by Microsoft Windows Server Update Services (WSUS). This inventory tool can be used only in an SMS 2003 SP2 site hierarchy or an SMS 2003 SP1 site hierarchy with certain hotfixes applied.

The problem that is described in the "Symptoms" section resembles the problem that is documented in Microsoft Knowledge Base article 900638. However, be aware that the workarounds that are included in the following article may only be partially effective.