We have been fortunate in that a lot of our clients have not been hit by the WSUS-MSI-SVCHost issue. Essentially, the CPU hits 100% because of the SVCHost process and doesn't seem to relax at all.
The client computer is seemingly locked up with no way to end it other than rebooting. This had a deeper impact on companies with older hardware.
It eventually became apparent that there was a problem in the WSUS 2.x update system on XP clients.
A series of patches were released that did not fix the problem for most clients.
The last patch, Microsoft KB927891: You receive an access violation error when you try to install an update from Windows Update or from Microsoft Update after you apply hotfix package KB916089 does fix the problem to some degree. The system should no longer "freeze" after this patch is applied.
Note, that the system may still hit a high CPU usage amount, but the machine should still be usable.
If there are still issues, then install the following Microsoft KB932494: When you use Automatic Updates to scan for updates or to apply updates to applications that use Windows Installer, you experience issues that involve the Svchost.exe process.
This last update is actually the new WSUS 3.0 client. It should in fact fix the problem.
For SBSers, one should patch KB927891 on all XP Pro SP2 clients. Then one can install WSUS 3.0 on the server and the client will be delivered automatically. This way will save some time for you and your clients.
One of the original errors that came up: Application popup: svchost.exe - Application Error : The instruction at "0x745f2780" referenced memory at "0x00000070". The memory could not be "read". And, the original Microsoft KB916089: FIX: When you run Windows Update to scan for updates that use Windows Installer, including Office updates, CPU utilization may reach 100 percent for prolonged periods.
It would be nice if Microsoft would deliver KB927891 via WSUS so we can go ahead and update our SBS WSUS to 3.0.
We just finished trying to update an XP client with KB927891 and it didn't work. The system kept locking up with SVCHost at 100%. We set the Automatic Updates to manual, rebooted, reapplied the update, rebooted, and ran the WSUS 3.0 client update.
The WSUS 3.0 client install resets the service start from Manual to Automatic BTW.
Everything worked from there!
UPDATE 2007-05-22: Looks like the above wish for KB927891 being distributed via WSUS has become a reality:
So, after all of your workstations are confirmed to have received the update, backup your SBS servers, and go for WSUS 3.0!
WSUS 3.0 is available as an Update via WSUS too:
WSUS 3.0 can be manually downloaded here: Windows Server Update Services 3.0 which is the preferable method of install for us SBSers!
Remember, test these updates on virtual installations if you can first!
Thanks to Susan Bradly: So why isn't SBS 2003 R2 getting WSUS 3.0 as a critical update?.
Her article pointed to the WSUS Blog: Updates for WSUS available today.
Microsoft Small Business Specialists