Svchost is used for a variety of services, including Windows Update.
Recently there have been some issues with how Windows Update is searching for installed updates, that can lead to endless search time.
To fix this issue, first, we should confirm that we are having an issue with the Windows Update.
To do that we will rely on a tool called ProcExplorer (https://technet.microsoft.com/en-us/sysinternals/processexplorer.aspx).
Once installed open the tool and find in the list of processes svchost.exe.
Select the Threads tab (click ok if you get a warning about the debugger). This will show the running threads for the process.
If you have indeed the issue, there will be a high CPU usage on one thread. On the “Start Address” column check if the service being called is “wuauserv” (Windows Update Service).
Once this is confirmed we can proceed to “fixing the issue”. First stop the service by going to Control Panel -> System and Security -> Administrative Tools -> Services.
Search for the “Windows Update” service and stop it.
Once this is done you’ll need to download and install a tool named WSUS (http://download.wsusoffline.net/), that allows you to download and install windows updates offline.
Once installed open the UpdateGenerator.exe. This will open a window where you can select the updates you wish to download.
On the tab “Windows”, check the mark next to the type of your operating system (x86 / x64). Note that there are groups for Windows 7, 8 and 10, so make sure you are under the right group.
Once that is done press Start on the bottom.
This will download the updates to your machine, but it will not install them. That is done in a separate step.
Once the download is finished, open the UpdateInstaller.exe (usually under the client folder) and press Start.
This will install the downloaded updates.
You might have to do this several times in order to get all the updates you need for your machine, but it should take care of the endless search problem and high CPU usage.