Svchost.exe is known to cause high CPU usage problems. I’m sure you’ve been in a situation like this: you’re working on your computer and enjoying yourself when all of a sudden it becomes agonizingly slow and even starts freezing up. You press CTRL+ALT+DEL to open the Task Manager, click on the Processes tab,  and see that there are several instances of svchost.exe running and one of them is using up 90% - 100% of CPU! Some people will think: “OMG! My computer’s got a virus!!!�. Well, that might be true, because some malware masks itself as svchost, but most likely it’s just Windows being Windows.

So, what does svchost.exe do and why is it there in the first place? Svchost is there to host services and run DLLs. You might have noticed that most programs have their own .exe files and can run on their own. DLLs are different - they can’t launch themselves. Svchost.exe launches them and runs them. You can check out the FileInspect Process Library to find out more about the svchost.exe process.

Now the question is how to stop svchost.exe from stealing CPU usage. First of all, you’ll need to find out which of the svchost.exe instances is the culprit and is causing your computer to slow down. Also you need to identify the actual application running it.

Luckily, it’s easy.  There is a very useful free Microsoft (originally Sysinternals) tool called Process Explorer, that gives you detailed information for each running process. All you need to do is download it and click the .exe file - no installation is required.

Once you’ve got it running, hover the mouse point over each svchost.exe process and a tooltip windows with all the information needed will appear.

First of all, if the process that is eating up CPU is not a Windows process, kill it and uninstall the program that runs it. Also scan your computer for viruses and other malware.

However, most likely it will be a Windows process, such as Task Scheduler, firewall, or Windows Update. Sometimes simply restarting your computer gets rid of the problem. If not, try downloading the most recent Windows Updates. If for some reason you can’t, go to the Control Panel - Administrative Tools - double-click the Services shortcut (or click Start - Run - type in services.msc - hit Enter), find the required service, right-click on it, go to Properties and select Disabled from the Startup type box. You can always re-enable it later, so don’t worry. Reboot your computer and then go to the Microsoft website and download updates. Install them, re-enable the service that you have stopped, and restart again. Hopefully everything will be working now.

Another way to get rid of svchost.exe high CPU usage problem is to open the Task Manager (CTRL+ALT+DEL), find the process that is causing the problem, right-click on it, go to Set Priority and set it to Below Normal (or Idle if Below Normal doesn’t help). Keep in mind that setting it to Idle might interfere with your networking services, especially if you’re at work and part of a large network.

Also if you’re repeatedly getting svchost.exe errors, cleaning the Registry might help. If svchost was malware that you removed some time ago, and you are still getting the errors, there might be some bits of malware left in the Registry. You can download a good free Registry cleaner from Auslogics website.