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 ?