Hi,We installedthe critical update KB958644on a Windows Server 2008 machine 2 days ago and have experienceda massive increase in CPU utilisation, apparently for the System process. Our performance monitor reports typically showed the web server running in the 5-15% CPU utilisation range for the whole day even under fairly heavy load. For the last 2 days, the CPU graph now looks like an earthquake has hit and we have had to reboot the server both days to reset the CPU to normal.Today, the graph was showing 90%+ CPU utilisation and we were not able to RDP to the box and all web sites were non-responsive so had to get the ISP to do a hard reboot. The graph showed the server in this 90%+ CPU usage state for several hours before we were made aware of the problem so it was not just a temporary problem.Has anyone else had problems with this security update? If we have this problem again tomorrow, then I think we will have to uninstall the update and ensure we are as secure as possible with the workarounds in the technet article.Thanks,Jason

We are running a quad core Xeon Clovertown with 4GB RAM and Win 2008 Datacenter. CPU usage was a bit out of control again today so we uninstalled the update. Seems to have stabilised a little although still around 2-4X what we have been seeing for the same traffic volumes over the last 3 months. We have been running performance monitor reports with the System process being tracked and it is using 75%+ of the overall CPU utilisation which doesn't quite look right. It would account for the overall increase that we have seen but we are not sure what is causing it. Very coincidental that it all started happening after that update but things are still a little weird even after we uninstalled it. Could this be a hardware issue? Not seeing anything in the logs but maybe there are some diags we can run to check this out?

Hello, I would like to suggest that you post this in our Windows Update discussion newsgroup. People there are mainly focus on update related questions. They may help you to check out if it is an known issue or help you to efficiently resolve the problem. They may also share some useful information with you. http://www.microsoft.com/communities/newsgroups/en-us/default.aspx?dg=microsoft.public.windowsupdate&cat=en_US_2231886c-4c59-45b0-92e0-8881ddf5f40b&lang=en&cr=US Besides, regarding the high CPU utilization, you can try the Process Explorer and the Process Monitor to see if it can help you find out the cause: http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx In the Process Explorer, you can see if the System process is handling any unusually dlls or files, by clicking View (in the top menu) -> Lower Pane View -> DLLs or Handles. In the Process Monitor, you can filter only the System process by configuring the Filter: 1. Click the Filter icon on the menu bar or press Ctrl+L. 2. Remove all the existing filters and add the new filter: 'PID' 'is' '4' then 'Include'. 3. Right click on any column name (such as Path) and click Select Columns Check the Duration check box. 4. Then, find out which operation is consuming most of the time. Best regards,Chang Yin

We have isolated our problem to the AVG network filter driver. When this is enabled, CPU usage is much higher than usual and when we kick off a big download, CPU usage sky rockets.When we disable the AVG network filter driver, CPU usage returns to normal and does not spiral out of control when a big download is started.Our hosting provider has logged a support request with AVG and I will post back any updates.Jason