The title says it all. Since a few months, on every Windows 7 workstation I reinstall, the first check for updates takes several hours, during which there is no disk nor network activity but an svchost process is maxing out an entire CPU core and takes up about a GB of RAM.

Eventually once I let it run for several hours it finds the updates and starts installing them, so it's not an actual problem but still a big annoyance when I need to reinstall a machine for which I don't have an image ready.

Resetting Windows Update by stopping the services and deleting the SoftwareDistribution folder doesn't have any good effect and just makes the slow process restart from the beginning. Installing them manually via WSUSOffline still exhibits the same issue - it hangs for hours on "Listing IDs of installed updates" while svchost starts going crazy with CPU and RAM usage again.

There doesn't seem to be anything relevant in the event viewer - in the "Setup" category the last event is from "Servicing" saying that "KBWUClient-SelfUpdate-Aux" was successfully installed; there are no update-related errors of any kind. There is however a CAPI2 error saying "Failed extract of third-party root list from auto update cab at ... authrootstl.cab ... A required certificate is not within its validity period when verifying against the current system clock or the timestamp in the signed file", but I'm not sure whether it affects Windows Update. Needless to say, the system clock is correct.

This issue has been going on for months (including the CAPI error) and wastes hours of mine & my clients' time.

Does anyone have a solution ?

  • I'll edit the question and post the WindowsUpdate.log once this piece of garbage finally updates so I can open a browser without risking getting it compromised. Also sorry for the lack of formatting, I'm on mobile currently.
    – user316266
    Oct 12, 2015 at 19:21
  • This isn't really an answer but I've found that when this happens all I have to do is simply open the WindowsUpdate.log file and suddenly the thing decides to start working...
    – MetaGuru
    Nov 4, 2015 at 18:44
  • Just a thought, but it’s really quite easy to completely automate image creation and updating with MDT. You use a VM and a task sequence that both deploys and captures. It deploys your current image, updates it, then re-captures that image (all up-to-date) and then you wouldn’t need to do all of this manual updating every time you reimage/reinstall. Nov 5, 2015 at 0:18

1 Answer 1


an svchost process is maxing out an entire CPU core and takes up about a GB of RAM.

The high memory usage of svchost.exe is a known issue that Microsoft fixed.


Microsoft released a Windows Update Client Update which is part of the July 2016 Update Rollup to fix the long hang at Windows Update scan.

This update contains some improvements to Windows Update Client in Windows 7 Service Pack 1 (SP1). This includes the following:

  • An optimization that addresses long scan time for updates that's reported on some computers.
  1. Download:

  2. Stop Windows Update service. This speeds up the setup of MSU updates. This can be done from the command line, or from the service manager window.

  3. Try the downloaded update and see if it speeds up the installation of Updates.

To be able to install the update you first need to install the April 2015 servicing stack update for Windows 7 and Windows Server 2008 R2 update (again, stop WU service before trying to install the MSU).

Download (April 2015 servicing stack update):

32 Bit

64 Bit

Workaround 1

If this is still not helping to search for new updates, use WSUSOffline to get all the updates.

  • The question is how do I apply this patch if it's an update as well. How can I install an update but skip the "search for available updates" that comes before installing any update (even the one executed from a direct/offline) file.
    – Mike
    Sep 9, 2016 at 16:10
  • @Mike If you first install KB3050265, then KB3102810, the installers each skip right to the actual install. If you see them checking the system for more than a few seconds, I would assume that something is still missing from the system. Nov 5, 2016 at 18:31