Svchost.exe 100% CPU usage reducing
In this article I will observe most common reasons of “svchost.exe” process taking 30% – 50% and even up to 100% CPU and a lot of memory, which can result PC hanging and not responding. First thing for you to learn is that svchost.exe is not always a virus (in most cases its not). This is legal file located in System32 folder. This file is extremely important for your system as a lot of standard Windows services use it to run themselves. But, this is also true, that sometimes something go wrong and service start to work wrong way which causes svchost.exe malfunction.
You can fix Svchost.exe high CPU usage problem with Svchost Fix Wizard simple tool:
However, here is a list of known issues with svchost.exe taking lots of CPU:
Problem: You are using 3G/GSM internet connection and from time to time you mention that your PC freezes and one thread of svchost.exe is taking a lot of CPU.
Solution: There is a service in Windows that is responsible for such internet connections called “WWAN Autoconfig”
As you see this service is running under svchost.exe process in LocalServiceNoNetwork group. This service has a few dependencies. The first thing to do is to turn off this service and disable its autostart from the windows shown on the picture. If problem will go away you can try to fix this problem by switching to another type of internet connection, submit this problem to Microsoft support, search for newest driver for 3G-modem, update drivers for your network devices in Device Manager.
You can also try System File Checker utility built in Windows – here is instruction – SFC
Another case is when you really have infection that causes high CPU usage. Tool that is very helpful to determine this is called Process Explorer. Here is how infection can look like:
What to do in such case? First, kill this process with Process Explorer so it won’t prevent you from running antivirus. If you are using antivirus already – update it and perform full system scan. If you don’t have or you are not sure you can use standard for Windows with latest updates Microsoft Malicious Software Removal Tool:
You can run it by going to Start -> Run and typing
In Windows XP. In Windows Vista or Windows 7 you need to type
in search box and you will find icon for it:
Run the full scan of Malicious Software Removal Tool and it should find virus that causing your problem and remove it.
Finding Problematic Service
Last method that I will describe there is finding problematic service using Process Explorer and putting a service in its own Svchost thread. So after you started Process Explorer – sort processes by name and you will see several svchost.exe processes in a column. Right-click on each of it one by one by one until you will locate service that uses a lot of processor resources:
In this case you can see that Windows Updates service is causing it. You can try to fix it by resetting Windows Update as described in this article (at the bottom) – Reset Windows Update. But if this doesn’t help or you have problem with another service you can make in running under its own svchost thread.
Creating an own process for particular service.
In command prompt type:
sc config (service name) type= own
For example, for Windows Updates (wuauserv):
sc config wuauserv type= own
There should be space between the ‘=’ sign and ‘own’. You can find list of service abbreviations to use in command prompt here – Services Syntax.
Reverse command will be:
sc config wuauserv type= share
For this commands to complete, you need to reboot your PC. After this you will notice that there is svchost.exe process that contains only Windows Update service running under it.
If you are not sure how to perform above instructions download and run Svchost Fix Wizard.