If that doesn't work, than it is a hardware problem coming from the CPU itself (like a broken car engine that makes a strange noise after 10 years of using), or maybe is just the network adapter. But try that as a last resort: delete your partitions and create new ones (different sizes, just to be sure). This is because uses 25 of my 2(4)-core-CPU in other words a complete core.

So that was my solution, i have no idea if it might work for anyone else. Peter Erwin J16:50 Hello, I have noticed, that my CPU fan always runs on a high level. No more 100% CPU usage when opening browser and rich content page ! I reinstalled Windows by deleting all the partitions and creating 2 new ones. So, i believed it was a hardware problem, but someone suggested me that those 2 other partitions might be infected with something and causing the CPU to run wild. I've installed Mozilla Firefox, same problem, with a new clean Windows. Just after starting the browser (Internet Explorer on new Windows XP), i had exactly the same CPU problem. I reinstalled Windows and let D and E as they were. I had 3 partitions on that computer C,D and E. I've tried MalwareBytes, SpyBot Search and Destroy, Avira, Avast, Nod32, Pc Utilities and many other programs (anti spy, antivirus, anti malware, etc.), nothing, but nothing worked. So, let’s find out now why is Avast service using so much CPU and some quick fix to resolve this. But, like you, many other users have also asked the same question. So, if you wonder why is Avast using so much CPU, you are not the first one to ask it. Step 1 Open Control Panel on WIndows 7/10. Solution 2 Repair Avast Antivirus Program To Solve Avast High CPU Usage. When you want to solve Avast service high disk. The computer worked fine, maybe a little slow, but when i opened any sort of page with any browser the cpu was going up to 100% and was making my computer to run very slow. It consumes too much space and resources in your CPU that ends up slowing down the machine. How to Fix Avast Using Too Much CPU Issue Solution 1 Update To The Latest Version To Solve Avast High CPU Usage.

I actually had the same problem with one of my computers.

Avast taking too much cpu